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Previous Year Questions
The base of a regular pyramid is a square and each of the other four sides is an equilateral triangle, length of each side being 20 cm. The vertical height of the pyramid, in cm, is
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In an examination, the score of A was 10% less than that of B, the score of B was 25% more than that of C, and the score of C was 20% less than that of D. If A scored 72, then the score of D was
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In an examination, Rama's score was one-twelfth of the sum of the scores of Mohan and Anjali. After a review, the score of each of them increased by 6. The revised scores of Anjali, Mohan, and Rama were in the ratio 11:10:3. Then Anjali's score exceeded Rama's score by
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Anil alone can do a job in 20 days while Sunil alone can do it in 40 days. Anil starts the job, and after 3 days, Sunil joins him. Again, after a few more days, Bimal joins them and they together finish the job. If Bimal has done 10% of the job, then in how many days was the job done?
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John jogs on track A at 6 kmph and Mary jogs on track B at 7.5 kmph. The total length of tracks A and B is 325 metres. While John makes 9 rounds of track A, Mary makes 5 rounds of track B. In how many seconds will Mary make one round of track A?
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A cyclist leaves A at 10 am and reaches B at 11 am. Starting from 10:01 am, every minute a motorcycle leaves A and moves towards B. Forty-five such motorcycles reach B by 11 am. All motorcycles have the same speed. If the cyclist had doubled his speed, how many motorcycles would have reached B by the time the cyclist reached B?
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Explanatory Answer
It is given that the cyclist starts at 10:00 am from A and reaches B at 11:00 am
Now, Motorcyclists start every minute from 10:01 am, and 45 such motorcyclists reach B before
11:00 am
If they leave one by one every minute, the 45th motorcyclist would have left by 10:45 am to reach B
at 11:00 am.
Thus, time taken by one motorcyclist to reach B from A = 15 minutes.
Now, the cyclist doubles his speed. This means, he reaches B at 10:30 am
So, the last motorcyclist should have left A by 10:15 am
Thus, 15 motorcyclists would have reached B by the time the cyclist reaches B
Let A and B be two regular polygons having a and b sides, respectively. If b = 2a and each interior angle of B is 3/2 times each interior angle of A, then each interior angle, in degrees, of a regular polygon with a + b sides is
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In 2010, a library contained a total of 11500 books in two categories - fiction and non-fiction. In 2015, the library contained a total of 12760 books in these two categories. During this period, there was 10% increase in the fiction category while there was 12% increase in the non-fiction category. How many fiction books were in the library in 2015?
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Two circles, each of radius 4 cm, touch externally. Each of these two circles is touched externally by a third circle. If these three circles have a common tangent, then the radius of the third circle, in cm, is
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In a triangle ABC, medians AD and BE are perpendicular to each other, and have lengths
12 cm and 9 cm, respectively. Then, the area of triangle ABC, in sq cm, is
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The average of 30 integers is 5. Among these 30 integers, there are exactly 20 which do not exceed 5. What is the highest possible value of the average of these 20 integers?
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We are told that exactly 20 of the 30 integers do not exceed 5.
That means exactly 10 of the 30 integers do exceed 5.
In order to keep the average of the 20 integers as high as possible, we need to keep the average of
the 10 integers above 5 as low as possible. Since we are dealing with integers, the least value that
the 10 integers above 5 can take is 6.
So, the sum of the 10 integers = 10 * 6 = 60
So the sum of the remainng 20 integers = Total sum - 60 = 5 * 50 - 60 = 90
Hence the average of the remaining 20 is 90/20 = 4.5
What BEST can be concluded about the students who missed the Science examination?
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Explanatory Answer
We need to check only for the ones given in the options
Alva – Hindi = 75
Average of (80+75+70)/3 = 75
Deep – Hindi = 90
Average of (100+90+80)/3 = 90
Esha – Hindi = 85
This is not the average of best 3 or 2 subjects
Hence Alva and Deep.
How many out of these six students missed exactly one examination?
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Explanatory Answer
Now we know that Carl only missed maths and Esha only English.
One student who missed hindi also missed science
Exams which can be missed
Alva – Hindi or Science
Bithi – Social Science and Science
Carl – Mathematics
Deep – Hindi or science
Esha – English
Foni – English and Social Science
Hence 3
For how many students can we be definite about which examinations they missed?
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Explanatory Answer
Exams which can be missed
Alva – Hindi or Science
Bithi – Social Science and Science
Carl – Mathematics
Deep – Hindi or science
Esha – English
Foni – English and Social Science
Either Alva or Deep can be the one who missed both Hindi and Science. Rest we are definite
Hence 4 .
In a certain board examination, students were to appear for examination in five subjects: English, Hindi, Mathematics, Science and Social Science. Due to a certain emergency situation, a few of the examinations could not be conducted for some students. Hence, some students missed one examination and some others missed two examinations. Nobody missed more than two examinations.
The board adopted the following policy for awarding marks to students. If a student appeared in all five examinations, then the marks awarded in each of the examinations were on the basis of the scores obtained by them in those examinations.
If a student missed only one examination, then the marks awarded in that examination was the average of the best three among the four scores in the examinations they appeared for.
If a student missed two examinations, then the marks awarded in each of these examinations was the average of the best two among the three scores in the examinations they appeared for.
The marks obtained by six students in the examination are given in the table below. Each of them missed either one or two examinations.
The following facts are also known.
I. Four of these students appeared in each of the English, Hindi, Science, and Social Science examinations.
II. The student who missed the Mathematics examination did not miss any other examination.
Ill. One of the students who missed the Hindi examination did not miss any other examination. The other student who missed the Hindi examination also missed the Science examination.
Who among the following did not appear for the Mathematics examination?
Video Explanation

Explanatory Answer
In this we check for the 4 options
Carl – Mathematics score = 90
This is average of best three scores 100 + 80 + 90 = 270/3 = 90
Alva – Mathematics score = 70
This cannot be the average of best three or best 2 scores
Esha – Mathematics score = 95
This is her highest score hence this is not the possible answer
Foni - – Mathematics score = 78
This cannot be the average of best three or best 2 scores
Hence Answer is Carl.
Which students did not appear for the English examination?
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Explanatory Answer
Alva and Bithi have scored the highest in English, hence they haven’t missed it.
Carl and deep have the least score in English, hence they haven’t missed it.
Esha scored 80 which is the average of (95+85+60)/3 = 80
Foni scored 83 which is the average of (88+83+78)/3 = 83
What BEST can be concluded about the students who did not appear for the Hindi examination?
Video Explanation

Explanatory Answer
We need to check only for the ones given in the options
Alva – Hindi = 75
Average of (80+75+70)/3 = 75
Deep – Hindi = 90
Average of (100+90+80)/3 = 90
Esha – Hindi = 85
This is not the average of best 3 or 2 subjects
Hence Alva and Deep.
What BEST can be concluded about the students who missed the Science examination?
Video Explanation

Explanatory Answer
We need to check only for the ones given in the options
Alva – Hindi = 75
Average of (80+75+70)/3 = 75
Deep – Hindi = 90
Average of (100+90+80)/3 = 90
Esha – Hindi = 85
This is not the average of best 3 or 2 subjects
Hence Alva and Deep.
How many out of these six students missed exactly one examination?
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Explanatory Answer
Now we know that Carl only missed maths and Esha only English.
One student who missed hindi also missed science
Exams which can be missed
Alva – Hindi or Science
Bithi – Social Science and Science
Carl – Mathematics
Deep – Hindi or science
Esha – English
Foni – English and Social Science
Hence 3
For how many students can we be definite about which examinations they missed?
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Explanatory Answer
Exams which can be missed
Alva – Hindi or Science
Bithi – Social Science and Science
Carl – Mathematics
Deep – Hindi or science
Esha – English
Foni – English and Social Science
Either Alva or Deep can be the one who missed both Hindi and Science. Rest we are definite
Hence 4 .
Who among the following did not appear for the Mathematics examination?
Video Explanation

Explanatory Answer
In this we check for the 4 options
Carl – Mathematics score = 90
This is average of best three scores 100 + 80 + 90 = 270/3 = 90
Alva – Mathematics score = 70
This cannot be the average of best three or best 2 scores
Esha – Mathematics score = 95
This is her highest score hence this is not the possible answer
Foni - – Mathematics score = 78
This cannot be the average of best three or best 2 scores
Hence Answer is Carl.
Which students did not appear for the English examination?
Video Explanation

Explanatory Answer
Alva and Bithi have scored the highest in English, hence they haven’t missed it.
Carl and deep have the least score in English, hence they haven’t missed it.
Esha scored 80 which is the average of (95+85+60)/3 = 80
Foni scored 83 which is the average of (88+83+78)/3 = 83
What BEST can be concluded about the students who did not appear for the Hindi examination?
Video Explanation

Explanatory Answer
We need to check only for the ones given in the options
Alva – Hindi = 75
Average of (80+75+70)/3 = 75
Deep – Hindi = 90
Average of (100+90+80)/3 = 90
Esha – Hindi = 85
This is not the average of best 3 or 2 subjects
Hence Alva and Deep.
How many 4-digit numbers, each greater than 1000 and each having all four digits distinct, are there with 7 coming before 3?
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Explanatory Answer
3 cases:
• 7 is in first place: 3 can go to 3 places, remaining 2 places will have 8 & 7 possibilities each
Hence, possible numbers are 3*8*7 = 168
• 7 is in second place: 3 can go to 2 places, first place will have 7 possibilities (excluding 0), and
remaining place will also have 7 possibilities
Hence, possible numbers are 2*7*7 = 98
• 7 is in third place: 3 can only go to one place, remaining 2 places have 7 possibilities each
Hence, possible numbers are 1*7*7 = 49
Therefore, total number of possibilities are 168 + 98 + 49 = 315
A sum of money is split among Amal, Sunil and Mita so that the ratio of the shares of Amal and Sunil is 3:2, while the ratio of the shares of Sunil and Mita is 4:5. If the difference between the largest and the smallest of these three shares is Rs 400, then Sunil’s share, in rupees, is
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Aron bought some pencils and sharpeners. Spending the same amount of money as Aron, Aditya bought twice as many pencils and 10 less sharpeners. If the cost of one sharpener is 2 more than the cost of a pencil, then the minimum possible number of pencils bought by Aron and Aditya together is
Video Explanation

Explanatory Answer
Let cost of pencil be ‘x’ and sharpener be ‘x+2’.
Amount spent by Aron = p*x + s*(x+2)
Amount spent by Aditya = 2p*x + (s- 10)( x+2)
Therefore: px + sx + 2s = 2px + sx - 10x + 2s – 20
px - 10x - 20 = 0
x(p-10) = 20
Since p-10 > 0, p(min) = 11
Total pencils = p + 2p = 33
In May, John bought the same amount of rice and the same amount of wheat as he had bought in April, but spent 150 more due to price increase of rice and wheat by 20% and 12%, respectively. If John had spent 450 on rice in April, then how much did he spend on wheat in May?
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Explanatory Answer
In April, John bought ‘r’ amount of rice at ‘x’ price, and ‘w’ amount of wheat at ‘y’ price.
Money spent = r * x + w * y
Also, r*x = 450
In May, amount spent = r( 1.2x) + w(1.12y)
= 1.2r*x + 1.12w*y = (r*x + w*y) + 150
0.2r*x + 0.12w*y = 150
0.12w*y = 150 – 0.2*450 = 60
w*y = 60/0.12 = 500
Amount spent on wheat in May = 1.12*500 = 560
John takes twice as much time as Jack to finish a job. Jack and Jim together take one-thirds of the time to finish the job than John takes working alone. Moreover, in order to finish the job, John takes three days more than that taken by three of them working together. In how many days will Jim finish the job working alone?
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Explanatory Answer
Let’s assume the amount of work done by each person in a day:
John – x
Jack – 2x
If Jack and Jim together take 1/3 of the time that John takes, it means they together complete 3 times the work that John alone completes in a day.
Hence, Jack + Jim = 3x
Jim – x
Assuming the work to be done is 100 units.
Number of days taken by each person is:
John – 100/x
Jack – 50/x
Jim – 100/x
All 3 together – 25/x
Therefore, 100/x = 25/x + 3
100 = 25 + 3x
3x = 75
x = 25
Jim will finish the job alone in 100/x = 100/25 = 4 days
Let C1 and C2 be concentric circles such that the diameter of C1 is 2cm longer than that of C2. If a chord of C1 has length 6 cm and is a tangent to C2, then the diameter, in cm of C1 is
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Explanatory Answer
In the figure, ‘O’ is the centre of circles ‘C1’ and ‘C2’ with radii ‘ x ’ & ‘ y ’ respectively
If d1 – d2 = 2cm, x - y = 1cm
Hence, MB = 1cm
AB is a chord with 6cm length and tangent to C2.
Therefore, AN = NB = 3cm ; ON = y; OB = y + 1
In right triangle ONB:
(ON) 2 + (NB) 2 = (OB) 2
y 2 + 9 = (y+1) 2
9 = 2y + 1
2y + 8
y = 4
Therefore, x = y + 1 = 5cm
Diameter = 2x = 10cm
A and B are two points on a straight line. Ram runs from A to B while Rahim runs from B to A. After crossing each other, Ram and Rahim reach their destinations in one minutes and four minutes, respectively. If they start at the same time, then the ratio of Ram's speed to Rahim's speed is
Video Explanation

Explanatory Answer
Assuming Ram’s speed = ‘a’ and Rahim’s speed = ‘b’.
If they cross each other at time ‘t’:
Distance travelled by Ram = a*t
Distance travelled by Rahim = b*t
Further time taken by Ram to reach B = (Dist. Remaining/Speed) = (b*t)/a = 1min -------①
Similarly, further time taken by Rahim to reach A = (a*t)/b = 4min -------②
Assume ratio (a/b) = x
Therefore, ① becomes: t/x = 1 &
② becomes: t*x = 4
Multiplying both equations, we get: t 2 = 4
Therefore t = 2
Applying value of t, we get x = 2 = a/b
Two circular tracks T1 and T2 of radii 100 m and 20 m, respectively touch at a point A. Starting from A at the same time, Ram and Rahim are walking on track T1 and track T2 at speeds 15 km/hr and 5 km/hr respectively. The number of full rounds that Ram will make before he meets Rahim again for the first time is
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Explanatory Answer
Circumference of T1 = 2π*100 = 200π
Time taken by Ram to reach A again = 200π/15 = 40π/3
Circumference of T2 = 2π*20 = 40π
Time taken by Rahim to reach A again = 40π/5
Ratio of the time taken by Ram & Rahim = (40π/3) /( 40 π/5) = 5/3
Ratio of time is inverse of ratio of distance travelled
Therefore, ratio of rounds travelled by Ram : Rahim = 3:5
Ram makes 3 rounds before he meets Rahim again
In how many ways can a pair of integers (x , a) be chosen such that x2 − 2 | x | + | a - 2 | = 0 ?
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Explanatory Answer
\((x^{2}-5x+7)^{(x+1)}=1\)
2 cases:
• Power is 0
x + 1 = 0
x = -1
• \(x^{2}-5x+7=1\)
\(x^{2}-5x+6=0\)
\(x^{2}-2x-3x+6=0\)
\(x(x-2)-3(x-2)=0\)
\((x-2)(x-3)=0\)
\(x=2, x=3\)
• \(x^{2}-5x+7=-1\) ; Given power is even
\(x^{2}-5x+8=0\)
No real roots
Hence, 3 integers (-1, 2, 3) satisfy the given equation
Which institutes and vendors had more than one contracts in any year?
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Which of the following is true?
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In how many years during this period was there only one contract?
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What BEST can be concluded about the number of contracts in 2010?
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Which institutes had multiple contracts during the same year?
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Four institutes, A, B, C, and D, had contracts with four vendors W, X, Y, and Z during the ten calendar years from 2010 to 2019. The contracts were either multi-year contracts running for several consecutive years or single-year contracts. No institute had more than one contract with the same vendor. However, in a calendar year, an institute may have had contracts with multiple vendors, and a vendor may have had contracts with multiple institutes. It is known that over the decade, the institutes each got into two contracts with two of these vendors, and each vendor got into two contracts with two of these institutes.
The following facts are also known about these contracts.
I. Vendor Z had at least one contract in every year.
II. Vendor X had one or more contracts in every year up to 2015, but no contract in any year after that.
III. Vendor Y had contracts in 2010 and 2019. Vendor W had contracts only in 2012.
IV. There were five contracts in 2012.
V. There were exactly four multi-year contracts. Institute B had a 7-year contract, D had a 4-year contract, and A and C had one 3-year contract each. The other four contracts were single-year contracts.
VI. Institute C had one or more contracts in 2012 but did not have any contract in 2011.
VII. Institutes B and D each had exactly one contract in 2012. Institute D did not have any contract in 2010.
In which of the following years were there two or more contracts?
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Which of the following is true?
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In how many years during this period was there only one contract?
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What BEST can be concluded about the number of contracts in 2010?
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Explanatory Answer
Which institutes had multiple contracts during the same year?
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Explanatory Answer
Which institutes and vendors had more than one contracts in any year?
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Explanatory Answer
In which of the following years were there two or more contracts?
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The sum of perimeters of an equilateral triangle and a rectangle is 90 cm. The area, T, of the triangle and the area , R, of the rectangle, both in sq cm, satisfy the relationship R = T2. If the sides of the rectangle are in the ratio 1 : 3, then the length, in cm, of the longer side of the rectangle, is
Video Explanation

Explanatory Answer
Let side of triangle be ‘a’; Breadth of rectangle = x; Length of rectangle = 3x
Therefore: 3a + 2(x+3x) = 90
3a + 8x = 90 ----------( i )
Also, R = T 2
x *3x = ( Ö 3a 2 /4) 2
3x 2 = 3a 4 /16
x = a 2 /4
Hence ( i ) becomes:
3a + 8(a 2 /4) = 90
3a + 2a 2 = 90
2a 2 + 3a -90 = 0
Solving the quadratic equation, we get a = 6
x = 9 ; 3x = 27
Hence, longer side = 27
The distance from B to C is thrice that from A to B. Two trains travel from A to C via B. The speed of train 2 is double that of train 1 while traveling from A to B and their speeds are interchanged while traveling from B to C. The ratio of the time taken by train 1 to that taken by train 2 in travelling from A to C is
Video Explanation

Explanatory Answer
BC = 3*AB
AB = x, BC = 3x
Let 2 trains be T1 & T2.
From A to B: Speed of T1 = s; Speed of T2 = 2s
From B to C: Speed of T1 = 2s; Speed of T2 = s
Total time taken by T1 (t1) = (x/ s)+( 3x/2s) = 5x/2s
Total time taken by T2 (t2) = (x/2s) + 3x/s) = 7x/2s
Ratio t1:t2 = 5x/2s:7x/2s = 5:7
Let f(x) = x2 + ax + b and g(x) = f(x + 1) - f(x - 1). If f(x) ≥ 0 for all real x, and g(20) = 72, then the smallest possible value of b is
Video Explanation

Explanatory Answer
g( 20) = f(21) – f(19)
72 = 21 2 + 21a + b – (19 2 + 19a + b)
72 = 40*2 + 2a
2a = -8
a = -4
f(x) = x 2 - 4x + b
Now, f(x) ≥ 0 for all real x
Therefore, D ≤ 0
16 – 4b ≤ 0
16 ≤ 4b
4 ≤ b
Hence, smallest possible value of b is 4
Students in a college have to choose at least two subjects from chemistry, mathematics and physics. The number of students choosing all three subjects is 18, choosing mathematics as one of their subjects is 23 and choosing physics as one of their subjects is 25. The smallest possible number of students who could choose chemistry as one of their subjects is
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Explanatory Answer
We can summarize the information given in the question as per the above Venn diagram.
We can conclude that:
a + c = 5
b + c = 7
Hence, b – a = 2
We have to minimize a + b.
Assuming if a = 0
Then b = 2 & c = 5
Therefore, number of students choosing Chemistry as one subject = 18 + 2 = 20
If x and y are non-negative integers such that x + 9 = z, y + 1 = z and x + y < z + 5, then the maximum possible value of 2x + y equals
Video Explanation

Explanatory Answer
Acc. to the question:
x + 9 = z & y + 1 = z
Therefore, x + 9 = y + 1
y = x + 8
x + y < z + 5
x + x + 8 < x + 9 + 5
x < 6
Now, 2x + y = 2x + x + 8 = 3x + 8
For this to be maximum, x has to be maximum.
Maximum possible value of x = 5.
Therefore, max possible value of 3x + 8 = 3(5) + 8 = 23
Anil buys 12 toys and labels each with the same selling price. He sells 8 toys initially at 20% discount on the labeled price. Then he sells the remaining 4 toys at an additional 25% discount on the discounted price. Thus, he gets a total of Rs 2112, and makes a 10% profit. With no discounts, his percentage of profit would have been
Video Explanation

Explanatory Answer
Let common SP be x
For 8 toys, SP = 0.8x
For remaining 4 toys, SP = 0.75*0.8x = 0.6x
Total SP = 8* 0.8x + 4* 0.6x = 2112
6.4x + 2.4x = 2112
8.8x = 2112
x = 240
Also let Total Cost Price = y
2112 = 1.1y
y = 1920
With no discounts, Total SP = 12*240 = 2880
Profit = 2880-1920 = 960
Profit % = (960/ 1920)* 100 = 50%