Q1:

Time, Speed & Distance

Medium

Points A,P,QA, P, Q and BB lie on the same line such that P,QP, Q and BB are, respectively, 100 km,200 km100 \mathrm{~km}, 200 \mathrm{~km} and 300 km300 \mathrm{~km} away from AA. Cars 11 and 22 leave AA at the same time and move towards B.B. Simultaneously, car 33 leaves BB and moves towards AA. Car 33 meets car 11 at QQ, and car 22 at PP. If each car is moving in uniform speed then the ratio of the speed of car 22 to that of car 11 is

Answer options
Option 3
Correct Answer
Explanation for CAT QA question 1

Q2:

Time & Work

Medium

A water tank has inlets of two types AA and BB. All inlets of type AA when open, bring in water at the same rate. All inlets of type BB, when open, bring in water at the same rate. The empty tank is completely filled in 3030 minutes if 1010 inlets of type AA and 4545 inlets of type BB are open, and in 11 hour if 88 inlets of type AA and 1818 inlets of type BB are open. In how many minutes will the empty tank get completely filled if 77 inlets of type AA and 2727 inlets of type BB are open?

48
Correct Answer
Explanation for CAT QA question 2

Q3:

Inequalities

Medium

How many two-digit numbers, with a non-zero digit in the units place, are there which are more than thrice the number formed by interchanging the positions of its digits?

Answer options
Option 3
Correct Answer
Explanation for CAT QA question 3

Q4:

Time & Work

Hard

A tank is emptied everyday at a fixed time point. Immediately thereafter, either pump AA or pump BB or both start working until the tank is full. On Monday, AA alone completed filling the tank at 8pm8 \mathrm{pm}. On Tuesday, B alone completed filling the tank at 6pm6 \mathrm{pm}. On Wednesday, AA alone worked till 5pm5 \mathrm{pm}, and then B worked alone from 5pm5 \mathrm{pm} to 7pm7 \mathrm{pm}, to fill the tank. At what time was the tank filled on Thursday if both pumps were used simultaneously all along?

Answer options
Option 2
Correct Answer
Explanation for CAT QA question 4

Q5:

Quadrilaterals

Medium

The area of a rectangle and the square of its perimeter are in the ratio 1:251:25. Then the lengths of the shorter and longer sides of the rectangle are in the ratio

Answer options
Option 1
Correct Answer
Explanation for CAT QA question 5

Q6:

Inequalities

Easy

If the sum of squares of two numbers is 9797, then which one of the following cannot be their product?

Answer options
Option 1
Correct Answer
Explanation for CAT QA question 6

Q7:

Inequalities

Medium

If aa and bb are integers such that 2x2−ax+2>02x^2 - ax + 2 > 0 and x2−bx+8≥0x^2 −bx + 8 \geq 0 for all real numbers x,x, then the largest possible value of 2a−6b2a-6b is

36
Correct Answer
Explanation for CAT QA question 7

Q8:

Progression & Series

Hard

The value of the sum 7×11+11×15+15×19+⋯+95×997 \times 11 + 11 \times 15 + 15 \times 19 + \dots + 95 \times 99 is

Answer options
Option 3
Correct Answer
Explanation for CAT QA question 8

Q9:

Set Theory

Medium

If A={62n−35n−1:n=1,2,3,…}A=\left\{6^{2 n}-35 n-1: n=1,2,3, \ldots\right\} and B={35(n−1):n=1,2,3,…}B=\{35(n-1): n=1,2,3, \ldots\} then which of the following is true?

Answer options
Option 2
Correct Answer
Explanation for CAT QA question 9

Q10:

Permutation & Combination

Medium

In a tournament, there are 4343 junior level and 5151 senior level participants. Each pair of juniors play one match. Each pair of seniors play one match. There is no junior versus senior match. The number of girl versus girl matches in junior level is 153153, while the number of boy versus boy matches in senior level is 276276. The number of matches a boy plays against a girl is

1098
Correct Answer
Explanation for CAT QA question 10

Q11:

Circles

Medium

A chord of length 5 cm5 \mathrm{~cm} subtends an angle of 60∘60^{\circ} at the centre of a circle. The length, in cm , of a chord that subtends an angle of 120∘120^{\circ} at the centre of the same circle is

Answer options
Option 1
Correct Answer
Explanation for CAT QA question 11

Q12:

Circles

Medium

From a rectangle ABCDABCD of area 768 sq cm768 \text{ sq cm}, a semicircular part with diameter ABAB and area 72π sq cm72\pi \text{ sq cm} is removed. The perimeter of the leftover portion, in cm, is

Answer options
Option 2
Correct Answer
Explanation for CAT QA question 12

Q13:

Simple & Compound Interest

Medium

Gopal borrows Rs. XX from Ankit at 8%8 \% annual interest. He then adds Rs. YY of his own money and lends Rs. X+YX+Y to Ishan at 10%10 \% annual interest. At the end of the year, after returning Ankit's dues, the net interest retained by Gopal is the same as that accrued to Ankit. On the other hand, had Gopal lent Rs. X+2YX+2Y to Ishan at 10%10 \%, then the net interest retained by him would have increased by Rs. 150150. If all interests are compounded annually, then find the value of X+YX+Y.

4000
Correct Answer
Explanation for CAT QA question 13

Q14:

Logarithms

Medium

The smallest integer nn for which 4n>17194^n > 17^{19} holds, is closest to

Answer options
Option 1
Correct Answer
Explanation for CAT QA question 14

Q15:

Triangles

Medium

A triangle ABCABC has area 3232 sq units and its side BCBC , of length 88 units, lies on the line x=4\mathrm{x}=4. Then the shortest possible distance between AA and the point (0,0)(0,0) is

Answer options
Option 3
Correct Answer
Explanation for CAT QA question 15

Q16:

Set Theory

Medium

For two sets AA and BB, let AΔBA \Delta B denote the set of elements which belong to AA or BB but not both. If P={1,2,3,4},Q={2,3,5,6},,R={1,3,7,8,9},S=P=\{1,2,3,4\}, Q=\{2,3,5,6\},, R=\{1,3,7,8,9\}, S= {2,4,9,10}\{2,4,9,10\}, then the number of elements in (PΔQ)Δ(RΔS)(P \Delta Q) \Delta(R \Delta S) is

Answer options
Option 1
Correct Answer
Explanation for CAT QA question 16

Q17:

Logarithms

Medium

If p3=q4=r5=s6p^3 = q^4 = r^5 = s^6, then the value of log⁡s(pqr)\log_s(pqr) is equal to

Answer options
Option 4
Correct Answer
Explanation for CAT QA question 17

Q18:

Mixture & Alligation

Medium

There are two drums, each containing a mixture of paints AA and BB . In drum 1, A1, \mathrm{~A} and B are in the ratio 18:718: 7. The mixtures from drums 11 and 22 are mixed in the ratio 3:43: 4 and in this final mixture, AA and BB are in the ratio 13:713: 7. In drum 22, then AA and BB were in the ratio

Answer options
Option 1
Correct Answer
Explanation for CAT QA question 18

Q19:

Ratio, Proportion & Variation

Medium

The scores of Amal and Bimal in an examination are in the ratio 11:1411:14. After an appeal, their scores increase by the same amount and their new scores are in the ratio 47:5647 : 56. The ratio of Bimal's new score to that of his original score is

Answer options
Option 4
Correct Answer
Explanation for CAT QA question 19

Q20:

Mean, Median & Mode

Medium

The arithmetic mean of x,yx, y and zz is 8080, and that of x,y,z,ux, y, z, u and vv is 7575, where u=(x+y)/2u=(x+y) / 2 and v=(y+z)/2v=(y+z) / 2. If x≥zx \geq z, then the minimum possible value of xx is

105
Correct Answer
Explanation for CAT QA question 20

Q21:

Mixture & Alligation

Easy

The strength of a salt solution is p%p\% if 100ml100 \mathrm{ml} of the solution contains p grams of salt. If three salt solutions A,B,CA, B, C are mixed in the proportion 1:2:31: 2: 3, then the resulting solution has strength 20%20 \%. If instead the proportion is 3:2:13: 2: 1, then the resulting solution has strength 30%30 \%. A fourth solution, DD, is produced by mixing BB and CC in the ratio 2:72: 7. The ratio of the strength of DD to that of AA is

Answer options
Option 3
Correct Answer
Explanation for CAT QA question 21

Q22:

Time, Speed & Distance

Medium

Points AA and BB are 150 km150 \mathrm{~km} apart. Cars 11 and 22 travel from AA to BB, but car 22 starts from AA when car 11 is already 20 km20 \mathrm{~km} away from AA. Each car travels at a speed of 100kmph100 \mathrm{kmph} for the first 50 km50 \mathrm{~km}, at 50kmph50 \mathrm{kmph} for the next 50 km50 \mathrm{~km}, and at 25kmph25 \mathrm{kmph} for the last 50 km50 \mathrm{~km}. The distance, in km, between car 22 and BB when car 11 reaches BB is

5
Correct Answer
Explanation for CAT QA question 22

Q23:

Minima & Maxima

Medium

Let f(x)=f(x)= max{5x5x, 52−2x252-2x^2}, where xx is any positive real number. Then the minimum possible value of f(x)f(x) is

20
Correct Answer
Explanation for CAT QA question 23

Q24:

Logarithms

Medium

1log⁡2100−1log⁡4100+1log⁡5100−1log⁡10100+1log⁡20100−1log⁡25100+1log⁡50100= ?\dfrac{1}{\log _{2} 100}-\dfrac{1}{\log _{4} 100}+\dfrac{1}{\log _{5} 100}-\dfrac{1}{\log _{10} 100}+\dfrac{1}{\log _{20} 100}-\dfrac{1}{\log _{25} 100}+\dfrac{1}{\log _{50} 100}= \ ?

Answer options
Option 4
Correct Answer
Explanation for CAT QA question 24

Q25:

Progression & Series

Medium

Let t1,t2,…t_1, t_2, \dots be real numbers such that t1+t2+⋯+tn=2n2+9n+13t_1 + t_2 +\dots+ t_n = 2n^2 + 9n + 13, for every positive integer n≥2n\ge2. If tk=103t_k =103, then kk equals

24
Correct Answer
Explanation for CAT QA question 25

Q26:

Mixture & Alligation

Medium

A 20%20 \% ethanol solution is mixed with another ethanol solution, say, SS of unknown concentration in the proportion 1:31:3 by volume. This mixture is then mixed with an equal volume of 20%20 \% ethanol solution. If the resultant mixture is a 31.25%31.25 \% ethanol solution, then the unknown concentration of SS is

Answer options
Option 4
Correct Answer
Explanation for CAT QA question 26

Q27:

Circles

Medium

On a triangle ABCA B C, a circle with diameter BCB C is drawn, intersecting ABA B and ACA C at points PP and QQ, respectively. If the lengths of AB,ACA B, A C, and CPC P are 30 cm,25 cm30 \mathrm{~cm}, 25 \mathrm{~cm}, and 20 cm20 \mathrm{~cm} respectively, then the length of BQBQ , in cm , is

24
Correct Answer
Explanation for CAT QA question 27

Q28:

Inequalities

Medium

The smallest integer nn such that n3−11n2+32n−28>0n^3 - 11n^2 + 32n - 28 > 0 is

8
Correct Answer
Explanation for CAT QA question 28

Q29:

Minima & Maxima

Hard

Let a1,a2,…,a52a_{1}, a_{2}, \ldots, a_{52} be positive integers such that a1<a2<…<a52a_{1}<a_{2}<\ldots<a_{52}. Suppose, their arithmetic mean is one less than the arithmetic mean of a2,a3a_{2}, a_{3}, …,a52\ldots, a_{52}. If a52=100a_{52}=100, then the largest possible value of a1a_{1} is

Answer options
Option 2
Correct Answer
Explanation for CAT QA question 29

Q30:

Quadrilaterals

Hard

A parallelogram ABCDABCD has area 48sqcm48 \mathrm{sqcm}. If the length of CD is 8 cm8 \mathrm{~cm} and that of ADAD is s cm , then which one of the following is necessarily true?

Answer options
Option 4
Correct Answer
Explanation for CAT QA question 30

Q31:

Factorisation

Medium

If NN and xx are positive integers such that NN=2160N^{N}=2^{160} and N2+2NN^{2}+2 ^N is an integral multiple of 2x2^x, then the largest possible xx is

10
Correct Answer
Explanation for CAT QA question 31

Q32:

Time & Work

Medium

Ramesh and Ganesh can together complete a work in 1616 days. After seven days of working together, Ramesh got sick and his efficiency fell by 30%30 \%. As a result, they completed the work in 1717 days instead of 1616 days. If Ganesh had worked alone after Ramesh got sick, in how many days would he have completed the remaining work?

Answer options
Option 1
Correct Answer
Explanation for CAT QA question 32

Q33:

Time, Speed & Distance

Easy

On a long stretch of east-west road, AA and BB are two points such that BB is 350350 km west of AA. One car starts from AA and another from BB at the same time. If they move towards each other, then they meet after 11 hour. If they both move towards east, then they meet in 7hrs7 \mathrm{hrs}. The difference between their speeds, in km per hour, is

50
Correct Answer
Explanation for CAT QA question 33

Q34:

Mixture & Alligation

Medium

A jar contains a mixture of 175ml175 \mathrm{ml} water and 700ml700 \mathrm{ml} alcohol. Gopal takes out 10%10 \% of the mixture and substitutes it by water of the same amount. The process is repeated once again. The percentage of water in the mixture is now

Answer options
Option 4
Correct Answer
Explanation for CAT QA question 34

CAT 2018 Quantitative Ability Past Year Question Paper

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