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asked the doubt

Previous Year Questions
Among all the 12 departments (i.e., the 3 departments in each of the 4 cities), what was the maximum percentage increase in sales amount from 2018 to 2019?
Video Explanation

Explanatory Answer
From (4),
Increase in Electronics sales from 2018 to 2019:
(98+102+70+100) – (78+82+90+80) = 4 0 = Increase in Apparels sales from 2018 to 2019
• From (5),
Total sales in Home Décor in 2019 = 100+72+80+54 = 306
Hence, Total sales in Home Décor in 2018 = 306 – 70 = 236
From (6), we know sales of Home Décor in 2018 of Delhi and Bangalore.
80 + Z + 60 + Z = 236
2Z = 96
Z = 48
• From (7), we know that
Y – X = B – Y
2Y = B + X
B = 2Y – X -----------( i )
Also,
A – Y = 54 – X ---------(ii)
• F rom (8), we know that Y , 54, and B are in A.P.
54 – Y = B – 54
B = 108 – Y ----------(iii)
Therefore, from ( i ) we get
108 – Y = 2Y – X
X = 3Y – 108 ------------(iv)
And (ii) becomes:
A – Y = 54 – (3Y – 108)
A = 54 – 3Y + 108 + Y
A = 162 – 2Y ----------(v)
• From (4), we knew that
( Y +A+B+54) – (X+ Y+Y +X) = 4 0
Substituting values from (iii), (iv), and (v), we get:
(Y+162-2Y+108-Y+54) – (3Y-108 +Y+Y+3Y-108) = 40
324 – 2Y – 8Y + 216 = 40
10Y = 500
Y = 50
Therefore, we get values of A, B, and X by substituting values of Y.
A = 162 – 2Y = 162 – 100
A = 62
B = 108 – y = 108 – 50
B = 58
X = 3Y – 108 = 150 – 108
X = 42
Therefore, our final table looks like this:
We see maximum percentage increase in the Home Décor department in Mumbai, increasing from
48 to 72.
Increase = [(72-48)/ 48]* 100 = 50%
What was the total sales amount, in Crore Rupees, in 2019 for the chain of departmental stores?
Video Explanation

Explanatory Answer
From (4),
Increase in Electronics sales from 2018 to 2019:
(98+102+70+100) – (78+82+90+80) = 4 0 = Increase in Apparels sales from 2018 to 2019
• From (5),
Total sales in Home Décor in 2019 = 100+72+80+54 = 306
Hence, Total sales in Home Décor in 2018 = 306 – 70 = 236
From (6), we know sales of Home Décor in 2018 of Delhi and Bangalore.
80 + Z + 60 + Z = 236
2Z = 96
Z = 48
• From (7), we know that
Y – X = B – Y
2Y = B + X
B = 2Y – X -----------( i )
Also,
A – Y = 54 – X ---------(ii)
• F rom (8), we know that Y , 54, and B are in A.P.
54 – Y = B – 54
B = 108 – Y ----------(iii)
Therefore, from ( i ) we get
108 – Y = 2Y – X
X = 3Y – 108 ------------(iv)
And (ii) becomes:
A – Y = 54 – (3Y – 108)
A = 54 – 3Y + 108 + Y
A = 162 – 2Y ----------(v)
• From (4), we knew that
( Y +A+B+54) – (X+ Y+Y +X) = 4 0
Substituting values from (iii), (iv), and (v), we get:
(Y+162-2Y+108-Y+54) – (3Y-108 +Y+Y+3Y-108) = 40
324 – 2Y – 8Y + 216 = 40
10Y = 500
Y = 50
Therefore, we get values of A, B, and X by substituting values of Y.
A = 162 – 2Y = 162 – 100
A = 62
B = 108 – y = 108 – 50
B = 58
X = 3Y – 108 = 150 – 108
X = 42
Therefore, our final table looks like this:
Total sales amount in 2019:
(50 + 62 + 58 + 54) + (98 + 102 + 70 + 100) + (100 + 72 + 80 + 54)
= (224) + (370) + (306)
= 900 crores
A chain of departmental stores has outlets in Delhi, Mumbai, Bengaluru and Kolkata. The sales are categorized by its three departments – ‘Apparel’, ‘Electronics’, and ‘HomeDecor’. An Accountant has been asked to prepare a summary of the 2018 and 2019 sales amounts for an internal report. He has collated partial information and prepared the following table.
The following additional information is known.
1. The sales amounts in the Apparel departments were the same for Delhi and Kolkata in 2018.
2. The sales amounts in the Apparel departments were the same for Mumbai and Bengaluru in 2018. This sales amount matched the sales amount in the Apparel department for Delhi in 2019.
3. The sales amounts in the HomeDecor departments were the same for Mumbai and Kolkata in 2018.
4. The sum of the sales amounts of four Electronics departments increased by the same amount as the sum of the sales amounts of four Apparel departments from 2018 to 2019.
5. The total sales amounts of the four HomeDecor departments increased by Rs 70 Crores from 2018 to 2019.
6. The sales amounts in the HomeDecor departments of Delhi and Bengaluru each increased by Rs 20 Crores from 2018 to 2019.
7. The sales amounts in the Apparel departments of Delhi and Bengaluru each increased by the same amount in 2019 from 2018. The sales amounts in the Apparel departments of Mumbai and Kolkata also each increased by the same amount in 2019 from 2018.
8. The sales amounts in the Apparel departments of Delhi, Kolkata and Bengaluru in 2019 followed an Arithmetic Progression.
In HomeDecor departments of which cities were the sales amounts the highest in 2018 and 2019, respectively?
Video Explanation

Explanatory Answer
From (4),
Increase in Electronics sales from 2018 to 2019:
(98+102+70+100) – (78+82+90+80) = 4 0 = Increase in Apparels sales from 2018 to 2019
• From (5),
Total sales in Home Décor in 2019 = 100+72+80+54 = 306
Hence, Total sales in Home Décor in 2018 = 306 – 70 = 236
From (6), we know sales of Home Décor in 2018 of Delhi and Bangalore.
80 + Z + 60 + Z = 236
2Z = 96
Z = 48
• From (7), we know that
Y – X = B – Y
2Y = B + X
B = 2Y – X -----------( i )
Also,
A – Y = 54 – X ---------(ii)
• F rom (8), we know that Y , 54, and B are in A.P.
54 – Y = B – 54
B = 108 – Y ----------(iii)
Therefore, from ( i ) we get
108 – Y = 2Y – X
X = 3Y – 108 ------------(iv)
And (ii) becomes:
A – Y = 54 – (3Y – 108)
A = 54 – 3Y + 108 + Y
A = 162 – 2Y ----------(v)
• From (4), we knew that
( Y +A+B+54) – (X+ Y+Y +X) = 4 0
Substituting values from (iii), (iv), and (v), we get:
(Y+162-2Y+108-Y+54) – (3Y-108 +Y+Y+3Y-108) = 40
324 – 2Y – 8Y + 216 = 40
10Y = 500
Y = 50
Therefore, we get values of A, B, and X by substituting values of Y.
A = 162 – 2Y = 162 – 100
A = 62
B = 108 – y = 108 – 50
B = 58
X = 3Y – 108 = 150 – 108
X = 42
Therefore, our final table looks like this:
We can see form the table that Delhi had the highest sales amount in Home Décor in both the
years.
What was the increase in sales amount, in Crore Rupees, in the Apparel department of Mumbai from 2018 to 2019?
Video Explanation

Explanatory Answer
From (4),
Increase in Electronics sales from 2018 to 2019:
(98+102+70+100) – (78+82+90+80) = 4 0 = Increase in Apparels sales from 2018 to 2019
• From (5),
Total sales in Home Décor in 2019 = 100+72+80+54 = 306
Hence, Total sales in Home Décor in 2018 = 306 – 70 = 236
From (6), we know sales of Home Décor in 2018 of Delhi and Bangalore.
80 + Z + 60 + Z = 236
2Z = 96
Z = 48
• From (7), we know that
Y – X = B – Y
2Y = B + X
B = 2Y – X -----------( i )
Also,
A – Y = 54 – X ---------(ii)
• F rom (8), we know that Y , 54, and B are in A.P.
54 – Y = B – 54
B = 108 – Y ----------(iii)
Therefore, from ( i ) we get
108 – Y = 2Y – X
X = 3Y – 108 ------------(iv)
And (ii) becomes:
A – Y = 54 – (3Y – 108)
A = 54 – 3Y + 108 + Y
A = 162 – 2Y ----------(v)
• From (4), we knew that
( Y +A+B+54) – (X+ Y+Y +X) = 4 0
Substituting values from (iii), (iv), and (v), we get:
(Y+162-2Y+108-Y+54) – (3Y-108 +Y+Y+3Y-108) = 40
324 – 2Y – 8Y + 216 = 40
10Y = 500
Y = 50
Therefore, we get values of A, B, and X by substituting values of Y.
A = 162 – 2Y = 162 – 100
A = 62
B = 108 – y = 108 – 50
B = 58
X = 3Y – 108 = 150 – 108
X = 42
Therefore, our final table looks like this:
Mumbai’s sales in Apparel department increased by 12 crores (62cr – 50cr)
Among all the 12 departments (i.e., the 3 departments in each of the 4 cities), what was the maximum percentage increase in sales amount from 2018 to 2019?
Video Explanation

Explanatory Answer
From (4),
Increase in Electronics sales from 2018 to 2019:
(98+102+70+100) – (78+82+90+80) = 4 0 = Increase in Apparels sales from 2018 to 2019
• From (5),
Total sales in Home Décor in 2019 = 100+72+80+54 = 306
Hence, Total sales in Home Décor in 2018 = 306 – 70 = 236
From (6), we know sales of Home Décor in 2018 of Delhi and Bangalore.
80 + Z + 60 + Z = 236
2Z = 96
Z = 48
• From (7), we know that
Y – X = B – Y
2Y = B + X
B = 2Y – X -----------( i )
Also,
A – Y = 54 – X ---------(ii)
• F rom (8), we know that Y , 54, and B are in A.P.
54 – Y = B – 54
B = 108 – Y ----------(iii)
Therefore, from ( i ) we get
108 – Y = 2Y – X
X = 3Y – 108 ------------(iv)
And (ii) becomes:
A – Y = 54 – (3Y – 108)
A = 54 – 3Y + 108 + Y
A = 162 – 2Y ----------(v)
• From (4), we knew that
( Y +A+B+54) – (X+ Y+Y +X) = 4 0
Substituting values from (iii), (iv), and (v), we get:
(Y+162-2Y+108-Y+54) – (3Y-108 +Y+Y+3Y-108) = 40
324 – 2Y – 8Y + 216 = 40
10Y = 500
Y = 50
Therefore, we get values of A, B, and X by substituting values of Y.
A = 162 – 2Y = 162 – 100
A = 62
B = 108 – y = 108 – 50
B = 58
X = 3Y – 108 = 150 – 108
X = 42
Therefore, our final table looks like this:
We see maximum percentage increase in the Home Décor department in Mumbai, increasing from
48 to 72.
Increase = [(72-48)/ 48]* 100 = 50%
What was the total sales amount, in Crore Rupees, in 2019 for the chain of departmental stores?
Video Explanation

Explanatory Answer
From (4),
Increase in Electronics sales from 2018 to 2019:
(98+102+70+100) – (78+82+90+80) = 4 0 = Increase in Apparels sales from 2018 to 2019
• From (5),
Total sales in Home Décor in 2019 = 100+72+80+54 = 306
Hence, Total sales in Home Décor in 2018 = 306 – 70 = 236
From (6), we know sales of Home Décor in 2018 of Delhi and Bangalore.
80 + Z + 60 + Z = 236
2Z = 96
Z = 48
• From (7), we know that
Y – X = B – Y
2Y = B + X
B = 2Y – X -----------( i )
Also,
A – Y = 54 – X ---------(ii)
• F rom (8), we know that Y , 54, and B are in A.P.
54 – Y = B – 54
B = 108 – Y ----------(iii)
Therefore, from ( i ) we get
108 – Y = 2Y – X
X = 3Y – 108 ------------(iv)
And (ii) becomes:
A – Y = 54 – (3Y – 108)
A = 54 – 3Y + 108 + Y
A = 162 – 2Y ----------(v)
• From (4), we knew that
( Y +A+B+54) – (X+ Y+Y +X) = 4 0
Substituting values from (iii), (iv), and (v), we get:
(Y+162-2Y+108-Y+54) – (3Y-108 +Y+Y+3Y-108) = 40
324 – 2Y – 8Y + 216 = 40
10Y = 500
Y = 50
Therefore, we get values of A, B, and X by substituting values of Y.
A = 162 – 2Y = 162 – 100
A = 62
B = 108 – y = 108 – 50
B = 58
X = 3Y – 108 = 150 – 108
X = 42
Therefore, our final table looks like this:
Total sales amount in 2019:
(50 + 62 + 58 + 54) + (98 + 102 + 70 + 100) + (100 + 72 + 80 + 54)
= (224) + (370) + (306)
= 900 crores
In HomeDecor departments of which cities were the sales amounts the highest in 2018 and 2019, respectively?
Video Explanation

Explanatory Answer
From (4),
Increase in Electronics sales from 2018 to 2019:
(98+102+70+100) – (78+82+90+80) = 4 0 = Increase in Apparels sales from 2018 to 2019
• From (5),
Total sales in Home Décor in 2019 = 100+72+80+54 = 306
Hence, Total sales in Home Décor in 2018 = 306 – 70 = 236
From (6), we know sales of Home Décor in 2018 of Delhi and Bangalore.
80 + Z + 60 + Z = 236
2Z = 96
Z = 48
• From (7), we know that
Y – X = B – Y
2Y = B + X
B = 2Y – X -----------( i )
Also,
A – Y = 54 – X ---------(ii)
• F rom (8), we know that Y , 54, and B are in A.P.
54 – Y = B – 54
B = 108 – Y ----------(iii)
Therefore, from ( i ) we get
108 – Y = 2Y – X
X = 3Y – 108 ------------(iv)
And (ii) becomes:
A – Y = 54 – (3Y – 108)
A = 54 – 3Y + 108 + Y
A = 162 – 2Y ----------(v)
• From (4), we knew that
( Y +A+B+54) – (X+ Y+Y +X) = 4 0
Substituting values from (iii), (iv), and (v), we get:
(Y+162-2Y+108-Y+54) – (3Y-108 +Y+Y+3Y-108) = 40
324 – 2Y – 8Y + 216 = 40
10Y = 500
Y = 50
Therefore, we get values of A, B, and X by substituting values of Y.
A = 162 – 2Y = 162 – 100
A = 62
B = 108 – y = 108 – 50
B = 58
X = 3Y – 108 = 150 – 108
X = 42
Therefore, our final table looks like this:
We can see form the table that Delhi had the highest sales amount in Home Décor in both the
years.
A shopping mall has a large basement parking lot with parking slots painted in it along a single row. These slots are quite narrow; a compact car can fit in a single slot but an SUV requires two slots. When a car arrives, the parking attendant guides the car to the first available slot from the beginning of the row into which the car can fit.
For our purpose, cars are numbered according to the order in which they arrive at the lot. For example, the first car to arrive is given a number 1, the second a number 2, and so on. This numbering does not indicate whether a car is a compact or an SUV. The configuration of a parking lot is a sequence of the car numbers in each slot. Each single vacant slot is represented by letter V.
For instance, suppose cars numbered 1 through 5 arrive and park, where cars 1, 3 and 5 are compact cars and 2 and 4 are SUVs. At this point, the parking lot would be described by the sequence 1, 2, 3, 4, 5. If cars 2 and 5 now vacate their slots, the parking lot would now be described as 1, V, V, 3, 4. If a compact car (numbered 6) arrives subsequently followed by an SUV (numbered 7), the parking lot would be described by the sequence 1, 6, V, 3, 4, 7.
Answer the following questions INDEPENDENTLY of each other.
Initially cars numbered 1, 2, 3, and 4 arrive among which 1 and 4 are SUVs while 2 and 3 are compact cars. Car 1 then leaves, followed by the arrivals of car 5 (a compact car) and car 6 (an SUV). Car 4 then leaves. Then car 7 (an SUV) and car 8 (a compact car) arrive. At this moment, which among the following numbered car is parked next to car 3?
Video Explanation

Explanatory Answer
Hence, cars 7 & 2 are parked near car 3.
Suppose eight cars have arrived, of which two have left. Also suppose that car 4 is a compact and car 7 is an SUV. Which of the following is a POSSIBLE current configuration of the parking lot?
Video Explanation

Explanatory Answer
From the options, we can understand that initially, cars 1-6 were in the lot, post which 1 & 4 left
and 7 & 8 came in.
Suppose the sequence at some point of time is 4, 5, 6, V, 3. Which of the following is NOT necessarily true?
Video Explanation

Explanatory Answer
4, 6, 5, V, 3
• This tells us that 1 & 2 have left and 4, 5, and 6 have joined after 3 entered and 1 & 2 left.
• Also, this implies that 1 & 2 leaving has accommodated 4 positions: 4, 5, 6, & V.
• Therefore, 1 & 2 must be SUVs, and 4, 5, & 6 must be compacts. Nothing can be concluded about
Car 3.
Suppose that car 4 is not the first car to leave and that the sequence at a time between the arrival of the car 7 and car 8 is V, 7, 3, 6, 5. Then which of the following statements MUST be false?
Video Explanation

Explanatory Answer
V, 7, 3, 6, 5
Initial sequence could be 1, 2, 3, 4, 5
Now, we know that 4 was not the first car to leave. However, 6 is the next car and is taking the
position of 4.
The possibilities could be:
• 1 leaves , followed by 4, OR
• 2 leaves, followed by 4
In either case, the positions after both cars leaving would be 1, V, 3, V, 5 or V, 2, 3, V, 5.
Now, 6 arrives and takes the position of 4, skipping the initial vacant position in both cases. This
is only possible when the first vacant position is not enough to accommodate Car 6. Hence, Car
6 must be an SUV.
Initially cars numbered 1, 2, 3, and 4 arrive among which 1 and 4 are SUVs while 2 and 3 are compact cars. Car 1 then leaves, followed by the arrivals of car 5 (a compact car) and car 6 (an SUV). Car 4 then leaves. Then car 7 (an SUV) and car 8 (a compact car) arrive. At this moment, which among the following numbered car is parked next to car 3?
Video Explanation

Explanatory Answer
Hence, cars 7 & 2 are parked near car 3.
Suppose eight cars have arrived, of which two have left. Also suppose that car 4 is a compact and car 7 is an SUV. Which of the following is a POSSIBLE current configuration of the parking lot?
Video Explanation

Explanatory Answer
From the options, we can understand that initially, cars 1-6 were in the lot, post which 1 & 4 left
and 7 & 8 came in.
Suppose the sequence at some point of time is 4, 5, 6, V, 3. Which of the following is NOT necessarily true?
Video Explanation

Explanatory Answer
4, 6, 5, V, 3
• This tells us that 1 & 2 have left and 4, 5, and 6 have joined after 3 entered and 1 & 2 left.
• Also, this implies that 1 & 2 leaving has accommodated 4 positions: 4, 5, 6, & V.
• Therefore, 1 & 2 must be SUVs, and 4, 5, & 6 must be compacts. Nothing can be concluded about
Car 3.
Suppose that car 4 is not the first car to leave and that the sequence at a time between the arrival of the car 7 and car 8 is V, 7, 3, 6, 5. Then which of the following statements MUST be false?
Video Explanation

Explanatory Answer
V, 7, 3, 6, 5
Initial sequence could be 1, 2, 3, 4, 5
Now, we know that 4 was not the first car to leave. However, 6 is the next car and is taking the
position of 4.
The possibilities could be:
• 1 leaves , followed by 4, OR
• 2 leaves, followed by 4
In either case, the positions after both cars leaving would be 1, V, 3, V, 5 or V, 2, 3, V, 5.
Now, 6 arrives and takes the position of 4, skipping the initial vacant position in both cases. This
is only possible when the first vacant position is not enough to accommodate Car 6. Hence, Car
6 must be an SUV.
The local office of the APP-CAB company evaluates the performance of five cab drivers, Arun,
Barun, Chandan, Damodaran, and Eman for their monthly payment based on ratings in five
different parameters (P1 to P5) as given below:
P1: timely arrival
P2: behaviour
P3: comfortable ride
P4: driver's familiarity with the route
P5: value for money
Based on feedback from the customers, the office assigns a rating from 1 to 5 in each of these
parameters. Each rating is an integer from a low value of 1 to a high value of 5. The final rating
of a driver is the average of his ratings in these five parameters. The monthly payment of the
drivers has two parts – a fixed payment and final rating-based bonus. If a driver gets a rating of 1
in any of the parameters, he is not eligible to get bonus. To be eligible for bonus a driver also
needs to get a rating of five in at least one of the parameters.
The partial information related to the ratings of the drivers in different parameters and the
monthly payment structure (in rupees) is given in the table below:
The following additional facts are known.
1. Arun and Barun have got a rating of 5 in exactly one of the parameters. Chandan has got a
rating of 5 in exactly two parameters.
2. None of drivers has got the same rating in three parameters.
If Damodaran does not get a bonus, what is the maximum possible value of his final rating?
Video Explanation

Explanatory Answer
If Eman gets a bonus, what is the minimum possible value of his final rating?
Video Explanation

Explanatory Answer
If all five drivers get bonus, what is the minimum possible value of the monthly payment (in rupees) that a driver gets?
Video Explanation

Explanatory Answer
If all five drivers get bonus, what is the maximum possible value of the monthly payment (in rupees) that a driver gets?
Video Explanation

Explanatory Answer
If Damodaran does not get a bonus, what is the maximum possible value of his final rating?
Video Explanation

Explanatory Answer
If Eman gets a bonus, what is the minimum possible value of his final rating?
Video Explanation

Explanatory Answer
If all five drivers get bonus, what is the minimum possible value of the monthly payment (in rupees) that a driver gets?
Video Explanation

Explanatory Answer
If all five drivers get bonus, what is the maximum possible value of the monthly payment (in rupees) that a driver gets?
Video Explanation

Explanatory Answer
Twenty five coloured beads are to be arranged in a grid comprising of five rows and five columns. Each cell in the grid must contain exactly one bead. Each bead is coloured either Red, Blue or Green.
While arranging the beads along any of the five rows or along any of the five columns, the rules given below are to be followed:
1. Two adjacent beads along the same row or column are always of different colours.
2. There is at least one Green bead between any two Blue beads along the same row or column.
3. There is at least one Blue and at least one Green bead between any two Red beads along the same row or column.
Every unique, complete arrangement of twenty five beads is called a configuration.
The total number of possible congurations using beads of only two colours is:
Video Explanation

Explanatory Answer
Rules:
• Adjacent beads of different colours
• At least one green bead between any 2 blue beads
• At least one green & at least one blue bead between any 2 red beads
It is clear that using Red would require the other 2 colours too. Hence, combinations of Red +
Blue and Red + Green are not possible.
Using Blue + Green combination:
2 arrangements are possible
What is the maximum possible number of Red beads that can appear in any conguration?
Video Explanation

Explanatory Answer
Maximum number of Red beads possible in a configuration = 9
What is the minimum number of Blue beads in any conguration?
Video Explanation

Explanatory Answer
Minimum number of Blue beads possible in a configuration = 6
Two Red beads have been placed in ‘second row, third column’ and ‘third row, second column’. How many more Red beads can be placed so as to maximise the number of Red beads used in the configuration?
Video Explanation

Explanatory Answer
If we place 2 red beads at R2-C3 and R3-C2, the rest of the red beads can be maximised in the
following way:
A total of 8 red beads can be placed in this configuration. Hence, we can place 6 more red
beads to maximise their number.
The total number of possible congurations using beads of only two colours is:
Video Explanation

Explanatory Answer
Rules:
• Adjacent beads of different colours
• At least one green bead between any 2 blue beads
• At least one green & at least one blue bead between any 2 red beads
It is clear that using Red would require the other 2 colours too. Hence, combinations of Red +
Blue and Red + Green are not possible.
Using Blue + Green combination:
2 arrangements are possible
What is the maximum possible number of Red beads that can appear in any conguration?
Video Explanation

Explanatory Answer
Maximum number of Red beads possible in a configuration = 9
What is the minimum number of Blue beads in any conguration?
Video Explanation

Explanatory Answer
Minimum number of Blue beads possible in a configuration = 6
Two Red beads have been placed in ‘second row, third column’ and ‘third row, second column’. How many more Red beads can be placed so as to maximise the number of Red beads used in the configuration?
Video Explanation

Explanatory Answer
If we place 2 red beads at R2-C3 and R3-C2, the rest of the red beads can be maximised in the
following way:
A total of 8 red beads can be placed in this configuration. Hence, we can place 6 more red
beads to maximise their number.
Suppose vial C tests positive and vials A, E and H test negative. Which patient has the disease?
Video Explanation

Explanatory Answer
IF Vial C tests positive while A, E, H are negative then any patient with vial A, E, H will not have the disease.
Patient 8 and 14 have E hence they are negative. Patient 2 doesn’t have vial C hence it can’t be positive.
Patient 6 has vial C and none of A, E, H.
Suppose vial A tests positive and vials D and G test negative. Which of the following vials should we test next to identify the patient with the disease?
Video Explanation

Explanatory Answer
We see patients 9 to 16 have the vial A, among them patient 9 & 11 have vial D, 10 & 12 have vial D & G hence they cannot be disease positive. Patient 14 & 16 have vial G hence they also can’t test positive. Patient 13 – A, C, F, H and Patient 15 – A, C, E, H
Since A, C, H is common we must test either E or F to confirm the disease.
Which of the following combinations of test results is NOT possible?
Video Explanation

Explanatory Answer
Let’s look at possible positive patients with given conditions option-wise
• Patient 4 can be positive – B, D, E, G
• Patient 14 can be positive – A, C, F, G
• Patient 4 can be positive – B, D, E, H
• This case is not possible
Suppose one of the lab assistants accidentally mixed two patients' blood samples before they were distributed to the vials. Which of the following correctly represents the set of all possible numbers of positive test results out of the eight vials?
Video Explanation

Explanatory Answer
4 vials will definitely give us a positive result.
Patient 1 & 2 – 3 vials common and one unique each makes it 5 vials which can give us a positive result.
Patient 1 & 16 – 8 different vials which can lead to positive results
Our answer must contain 4, 5 and 8 which is only option B.
Suppose vial C tests positive and vials A, E and H test negative. Which patient has the disease?
Video Explanation

Explanatory Answer
IF Vial C tests positive while A, E, H are negative then any patient with vial A, E, H will not have the disease.
Patient 8 and 14 have E hence they are negative. Patient 2 doesn’t have vial C hence it can’t be positive.
Patient 6 has vial C and none of A, E, H.
Suppose vial A tests positive and vials D and G test negative. Which of the following vials should we test next to identify the patient with the disease?
Video Explanation

Explanatory Answer
We see patients 9 to 16 have the vial A, among them patient 9 & 11 have vial D, 10 & 12 have vial D & G hence they cannot be disease positive. Patient 14 & 16 have vial G hence they also can’t test positive. Patient 13 – A, C, F, H and Patient 15 – A, C, E, H
Since A, C, H is common we must test either E or F to confirm the disease.
Which of the following combinations of test results is NOT possible?
Video Explanation

Explanatory Answer
Let’s look at possible positive patients with given conditions option-wise
• Patient 4 can be positive – B, D, E, G
• Patient 14 can be positive – A, C, F, G
• Patient 4 can be positive – B, D, E, H
• This case is not possible
Suppose one of the lab assistants accidentally mixed two patients' blood samples before they were distributed to the vials. Which of the following correctly represents the set of all possible numbers of positive test results out of the eight vials?
Video Explanation

Explanatory Answer
4 vials will definitely give us a positive result.
Patient 1 & 2 – 3 vials common and one unique each makes it 5 vials which can give us a positive result.
Patient 1 & 16 – 8 different vials which can lead to positive results
Our answer must contain 4, 5 and 8 which is only option B.
What was the total number of schools having exactly three of the four facilities?
Video Explanation

Explanatory Answer
Assume only F1 & F2 = A
We know from condition 8 that F1 and F2 have 162 students
A + x + 40 + x = 162
F2 = 313 = 162 + 26 + 45 + 30 + x
x = 50 and A = 22
Now F1 & F4 have the same number of schools
We Calculate the values not common to both to balance the figures
F4 = 50 + 45 + 24 + 20 = 139
F1 = 50 + 25 + 22 + x = 139
x = 42
Now to calculate only F1 and F4
520 – 313 – 26 – 24 – 20 – 25 – 42 – 50 = 20
What was the number of schools having only facilities F1 and F4?
Video Explanation

Explanatory Answer
Assume only F1 & F2 = A
We know from condition 8 that F1 and F2 have 162 students
A + x + 40 + x = 162
F2 = 313 = 162 + 26 + 45 + 30 + x
x = 50 and A = 22
Now F1 & F4 have the same number of schools
We Calculate the values not common to both to balance the figures
F4 = 50 + 45 + 24 + 20 = 139
F1 = 50 + 25 + 22 + x = 139
x = 42
Now to calculate only F1 and F4
520 – 313 – 26 – 24 – 20 – 25 – 42 – 50 = 20
A survey of 600 schools in India was conducted to gather information about their online teaching learning processes (OTLP).
The following four facilities were studied.
F1: Own software for OTLP
F2: Trained teachers for OTLP
F3: Training materials for OTLP
F4: All students having Laptops
The following observations were summarized from the survey.
1. 80 schools did not have any of the four facilities – F1, F2, F3, F4.
2. 40 schools had all four facilities.
3. The number of schools with only F1, only F2, only F3, and only F4 was 25, 30, 26 and 20 respectively.
4. The number of schools with exactly three of the facilities was the same irrespective of which three were considered.
5. 313 schools had F2.
6. 26 schools had only F2 and F3 (but neither F1 nor F4).
7. Among the schools having F4, 24 had only F3, and 45 had only F2.
8. 162 schools had both F1 and F2.
9. The number of schools having F1 was the same as the number of schools having F4.
What was the number of schools having facilities F2 and F4?
Video Explanation

Explanatory Answer
Assume only F1 & F2 = A
We know from condition 8 that F1 and F2 have 162 students
A + x + 40 + x = 162
F2 = 313 = 162 + 26 + 45 + 30 + x
x = 50 and A = 22
Now F1 & F4 have the same number of schools
We Calculate the values not common to both to balance the figures
F4 = 50 + 45 + 24 + 20 = 139
F1 = 50 + 25 + 22 + x = 139
x = 42
Now to calculate only F1 and F4
520 – 313 – 26 – 24 – 20 – 25 – 42 – 50 = 20
What was the number of schools having only facilities F1 and F3?
Video Explanation

Explanatory Answer
Assume only F1 & F2 = A
We know from condition 8 that F1 and F2 have 162 students
A + x + 40 + x = 162
F2 = 313 = 162 + 26 + 45 + 30 + x
x = 50 and A = 22
Now F1 & F4 have the same number of schools
We Calculate the values not common to both to balance the figures
F4 = 50 + 45 + 24 + 20 = 139
F1 = 50 + 25 + 22 + x = 139
x = 42
Now to calculate only F1 and F4
520 – 313 – 26 – 24 – 20 – 25 – 42 – 50 = 20
What was the number of schools having only facilities F1 and F4?
Video Explanation

Explanatory Answer
Assume only F1 & F2 = A
We know from condition 8 that F1 and F2 have 162 students
A + x + 40 + x = 162
F2 = 313 = 162 + 26 + 45 + 30 + x
x = 50 and A = 22
Now F1 & F4 have the same number of schools
We Calculate the values not common to both to balance the figures
F4 = 50 + 45 + 24 + 20 = 139
F1 = 50 + 25 + 22 + x = 139
x = 42
Now to calculate only F1 and F4
520 – 313 – 26 – 24 – 20 – 25 – 42 – 50 = 20
What was the total number of schools having exactly three of the four facilities?
Video Explanation

Explanatory Answer
Assume only F1 & F2 = A
We know from condition 8 that F1 and F2 have 162 students
A + x + 40 + x = 162
F2 = 313 = 162 + 26 + 45 + 30 + x
x = 50 and A = 22
Now F1 & F4 have the same number of schools
We Calculate the values not common to both to balance the figures
F4 = 50 + 45 + 24 + 20 = 139
F1 = 50 + 25 + 22 + x = 139
x = 42
Now to calculate only F1 and F4
520 – 313 – 26 – 24 – 20 – 25 – 42 – 50 = 20
What was the number of schools having facilities F2 and F4?
Video Explanation

Explanatory Answer
Assume only F1 & F2 = A
We know from condition 8 that F1 and F2 have 162 students
A + x + 40 + x = 162
F2 = 313 = 162 + 26 + 45 + 30 + x
x = 50 and A = 22
Now F1 & F4 have the same number of schools
We Calculate the values not common to both to balance the figures
F4 = 50 + 45 + 24 + 20 = 139
F1 = 50 + 25 + 22 + x = 139
x = 42
Now to calculate only F1 and F4
520 – 313 – 26 – 24 – 20 – 25 – 42 – 50 = 20
What was the number of schools having only facilities F1 and F3?
Video Explanation

Explanatory Answer
Assume only F1 & F2 = A
We know from condition 8 that F1 and F2 have 162 students
A + x + 40 + x = 162
F2 = 313 = 162 + 26 + 45 + 30 + x
x = 50 and A = 22
Now F1 & F4 have the same number of schools
We Calculate the values not common to both to balance the figures
F4 = 50 + 45 + 24 + 20 = 139
F1 = 50 + 25 + 22 + x = 139
x = 42
Now to calculate only F1 and F4
520 – 313 – 26 – 24 – 20 – 25 – 42 – 50 = 20
The average time taken to deliver orders booked on a particular day is computed as follows. Let the number of orders delivered the next day be x and the number of orders delivered the day after be y. Then the average time to deliver order is (x+2y)/(x+y). On which of the following days was the average time taken to deliver orders booked the least?
Video Explanation

Explanatory Answer
XYZ organization got into the business of delivering groceries to home at the beginning of the last month. They have a two-day delivery promise. However, their deliveries are unreliable. An order booked on a particular day may be delivered the next day or the day after. If the order is not delivered at the end of two days, then the order is declared as lost at the end of the second day. XYZ then does not deliver the order, but informs the customer, marks the order as lost, returns the payment and pays a penalty for non-delivery.
The following table provides details about the operations of XYZ for a week of the last month. The first column gives the date, the second gives the cumulative number of orders that were booked up to and including that day. The third column represents the number of orders delivered on that day. The last column gives the cumulative number of orders that were lost up to and including that day.
It is known that the numbers of orders that were booked on the 11th, 12th, and 13th of the last month that took two days to deliver were 4, 6, and 8 respectively.
Among the following days, the largest fraction of orders booked on which day was lost?
Video Explanation

Explanatory Answer
On which of the following days was the number of orders booked the highest?
Video Explanation

Explanatory Answer
The delivery ratio for a given day is defined as the ratio of the number of orders booked on that day which are delivered on the next day to the number of orders booked on that day which are delivered on the second day after booking. On which of the following days, was the delivery ratio the highest?
Video Explanation

Explanatory Answer
The average time taken to deliver orders booked on a particular day is computed as follows. Let the number of orders delivered the next day be x and the number of orders delivered the day after be y. Then the average time to deliver order is (x+2y)/(x+y). On which of the following days was the average time taken to deliver orders booked the least?
Video Explanation

Explanatory Answer
Among the following days, the largest fraction of orders booked on which day was lost?
Video Explanation

Explanatory Answer
On which of the following days was the number of orders booked the highest?
Video Explanation

Explanatory Answer
The delivery ratio for a given day is defined as the ratio of the number of orders booked on that day which are delivered on the next day to the number of orders booked on that day which are delivered on the second day after booking. On which of the following days, was the delivery ratio the highest?
Video Explanation

Explanatory Answer
In which of the following rounds, was Arun DEFINITELY the only player to bid Hi?
Video Explanation

Explanatory Answer
The Hi-Lo game is a four-player game played in six rounds. In every round, each player chooses to bid Hi or Lo. The bids are made simultaneously. If all four bid Hi, then all four lose 1 point each. If three players bid Hi and one bids Lo, then the players bidding Hi gain 1 point each and the player bidding Lo loses 3 points. If two players bid Hi and two bid Lo, then the players bidding Hi gain 2 points each and the players bidding Lo lose 2 points each. If one player bids Hi and three bid Lo, then the player bidding Hi gains 3 points and the players bidding Lo lose 1 point each. If all four bid Lo, then all four gain 1 point each.
Four players Arun, Bankim, Charu, and Dipak played the Hi-Lo game. The following facts are known about their game:
1. At the end of three rounds, Arun had scored 6 points, Dipak had scored 2 points, Bankim and Charu had scored -2 points each.
2. At the end of six rounds, Arun had scored 7 points, Bankim and Dipak had scored -1 point each, and Charu had scored -5 points.
3. Dipak’s score in the third round was less than his score in the first round but was more than his score in the second round.
4. In exactly two out of the six rounds, Arun was the only player who bid Hi.
What were the bids by Arun, Bankim, Charu and Dipak, respectively in the first round?
Video Explanation

Explanatory Answer
In how many rounds did all four players make identical bids?
Video Explanation

Explanatory Answer
In which of the following rounds, was Arun DEFINITELY the only player to bid Hi?
Video Explanation

Explanatory Answer
What were the bids by Arun, Bankim, Charu and Dipak, respectively in the first round?
Video Explanation

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In how many rounds did all four players make identical bids?
Video Explanation

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How many pine trees did Chitra receive?
Video Explanation

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Who got the plot with the smallest number of trees and how many trees did that plot have?
Video Explanation

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Which of the following statements is NOT true?
Video Explanation

Explanatory Answer
Which column had the highest number of trees?
Video Explanation

Explanatory Answer
A farmer had a rectangular land containing 205 trees. He distributed that land among his four daughters – Abha, Bina, Chitra and Dipti by dividing the land into twelve plots along three rows (X,Y,Z) and four Columns (1,2,3,4) as shown in the figure below:
The plots in rows X, Y, Z contained mango, teak and pine trees respectively. Each plot had trees in non-zero multiples of 3 or 4 and none of the plots had the same number of trees. Each daughter got an even number of plots. In the figure, the number mentioned in top left corner of a plot is the number of trees in that plot, while the letter in the bottom right corner is the first letter of the name of the daughter who got that plot (For example, Abha got the plot in row Y and column 1 containing 21 trees). Some information in the figure got erased, but the following is known:
1. Abha got 20 trees more than Chitra but 6 trees less than Dipti.
2. The largest number of trees in a plot was 32, but it was not with Abha.
3. The number of teak trees in Column 3 was double of that in Column 2 but was half of that in Column 4.
4. Both Abha and Bina got a higher number of plots than Dipti.
5. Only Bina, Chitra and Dipti got corner plots.
6. Dipti got two adjoining plots in the same row.
7. Bina was the only one who got a plot in each row and each column.
8. Chitra and Dipti did not get plots which were adjacent to each other (either in row / column / diagonal).
9. The number of mango trees was double the number of teak trees.
How many mango trees were there in total?
Video Explanation

Explanatory Answer
Which of the following is the correct sequence of trees received by Abha, Bina, Chitra and Dipti in that order?
Video Explanation

Explanatory Answer
How many pine trees did Chitra receive?
Video Explanation

Explanatory Answer
Who got the plot with the smallest number of trees and how many trees did that plot have?
Video Explanation

Explanatory Answer
Which of the following statements is NOT true?
Video Explanation

Explanatory Answer
Which column had the highest number of trees?
Video Explanation

Explanatory Answer
How many mango trees were there in total?
Video Explanation

Explanatory Answer
Which of the following is the correct sequence of trees received by Abha, Bina, Chitra and Dipti in that order?
Video Explanation

Explanatory Answer
The COMPLETE list of customers who gave the maximum total rating points to Ravi is
Video Explanation

Explanatory Answer
Now how can we uniquely get 29 and 26
For 29: 5+7+8+9 = 29
For 26:
5+6+7+8 = 26
4+5+8+9 = 26
4+6+7+9 = 26
As per statement 4 Bihari gave the highest rating points in Packaging, and Chirag gave the highest rating points in Hygiene.
So Bihari gives Ravi a 9 in packaging which means the highest points in Hygiene can be 8 only as Chirag gives the highest points in Hygiene and he gives the same score in packaging too.
Also per statement 6 Atal’s rank based on Packaging is the same as that based on Hygiene. This is also true for Deepak, this means that Bihari will be second in Hygiene and thus gives 7 points
What rating did Atal give on Timeliness?
Video Explanation

Explanatory Answer
Now how can we uniquely get 29 and 26
For 29: 5+7+8+9 = 29
For 26:
5+6+7+8 = 26
4+5+8+9 = 26
4+6+7+9 = 26
As per statement 4 Bihari gave the highest rating points in Packaging, and Chirag gave the highest rating points in Hygiene.
So Bihari gives Ravi a 9 in packaging which means the highest points in Hygiene can be 8 only as Chirag gives the highest points in Hygiene and he gives the same score in packaging too.
Also per statement 6 Atal’s rank based on Packaging is the same as that based on Hygiene. This is also true for Deepak, this means that Bihari will be second in Hygiene and thus gives 7 points