CAT 2020Slot 3QAAll Questions

All 18 QA questions with detailed solutions and explanations.
Questions marked with this icon include a detailed solution explanation
Q1
AlgebraMedium
If $x_1=-1$ and $x_m=x_{m+1}+(m+1)$ for every positive integer m, then $X_{100}$ equals
Q2
ArithmeticMedium
A contractor agreed to construct a 6 km road in 200 days. He employed 140 persons for the work. After 60 days, he realized that only 1.5 km road has been completed. How many additional people would he need to employ in order to finish the work exactly on time?
...
Q3
Number SystemsMedium
Let m and n be natural numbers such that n is even and $0.2<\frac{m}{20},\frac{n}{m},\frac{n}{11}<0.5$. Then $m-2n$ equals
Q4
Number SystemsMedium
How many of the integers 1, 2, … , 120, are divisible by none of 2, 5 and 7?
Q5
AlgebraMedium
How many pairs(a, b) of positive integers are there such that $a\leq b$ and $ab=4^{2017}$ ?
Q6
AlgebraMedium
A batsman played n + 2 innings and got out on all occasions. His average score in these n + 2 innings was 29 runs and he scored 38 and 15 runs in the last two innings. The batsman scored less than 38 runs in each of the first n innings. In these n innings, his average score was 30 runs and lowest score was x runs. The smallest possible value of x is
...
Q7
Number SystemsHard
How many integers in the set {100, 101, 102, ..., 999} have at least one digit repeated?
Q8
Number SystemsHard
Let $N$, $x$ and $y$ be positive integers such that $N=x+y$, ${ }$ $2\lt x \lt 10$ ${ }$ and ${ }$ $14 \lt y \lt 23$. If $N \gt25$, then how many distinct values are possible for N?
...
Q9
AlgebraMedium
If $\log_{a}{30}=A,\log_{a}({\frac{5}{3}})=-B$ and $\log_2{a}=\frac{1}{3}$, then $\log_3{a}$ equals
Q10
AlgebraMedium
If a,b,c are non-zero and $14^a=36^b=84^c$, then $6b(\frac{1}{c}-\frac{1}{a})$ is equal to
Q11
ArithmeticMedium
A man buys 35 kg of sugar and sets a marked price in order to make a 20% profit. He sells 5 kg at this price, and 15 kg at a 10% discount. Accidentally, 3 kg of sugar is wasted. He sells the remaining sugar by raising the marked price by p percent so as to make an overall profit of 15%. Then p is nearest to
...
Q12
ArithmeticMedium
Vimla starts for office every day at 9 am and reaches exactly on time if she drives at her usual speed of 40 km/hr. She is late by 6 minutes if she drives at 35 km/hr. One day, she covers two-thirds of her distance to office in one-thirds of her usual total time to reach office, and then stops for 8 minutes. The speed, in km/hr, at which she should drive the remaining distance to reach office exactly on time is
...
Q13
ArithmeticMedium
Anil, Sunil, and Ravi run along a circular path of length 3 km, starting from the same point at the same time, and going in the clockwise direction. If they run at speeds of 15 km/hr, 10 km/hr, and 8 km/hr, respectively, how much distance in km will Ravi have run when Anil and Sunil meet again for the first time at the starting point?
...
Q14
AlgebraMedium
The area, in sq. units, enclosed by the lines $x=2,y=\mid x-2\mid+4$, the X-axis and the Y-axis is equal to
Q15
AlgebraMedium
If $f(x+y)=f(x)f(y)$ and $f(5)=4$, then $f(10)-f(-10)$ is equal to
Q16
ArithmeticEasy
A and B are two railway stations 90 km apart. A train leaves A at 9:00 am, heading towards B at a speed of 40 km/hr. Another train leaves B at 10:30 am, heading towards A at a speed of 20 km/hr. The trains meet each other at
...
Q17
ArithmeticEasy
In the final examination, Bishnu scored 52% and Asha scored 64%. The marks obtained by Bishnu is 23 less, and that by Asha is 34 more than the marks obtained by Ramesh. The marks obtained by Geeta, who scored 84%, is
...
Q18
AlgebraMedium
Let m and n be positive integers, If $x^{2}+mx+2n=0$ and $x^{2}+2nx+m=0$ have real roots, then the smallest possible value of $m+n$ is