# CAT Number System Questions for Practice

Question 1:
Convert the number 1982 from base 10 to base 12. The result is
Topic: Base System

[1] 1182
[2] 1912
[3] 1192
[4] 1292

Question 2:
Let x, y and z be distinct integers. x and y are odd and positive, and z is even and positive. Which one of the following statements cannot be true?
Topic: Basics

[1] y(x – z)2is even
[2] y2(x – z) is odd
[3] y(x – z) is odd
[4] z(x – y)2is even

Question 3:
A red light flashes three times per minute and a green light flashes five times in 2 min at regular intervals.If both lights start flashing at the same time, how many times do they flash together in each hour?
Topic: HCF LCM

[1] 30
[2] 24
[3] 20
[4] 60

Question 4:
In a four-digit number, the sum of the first 2 digits is equal to that of the last 2 digits. The sum of the first and last digits is equal to the third digit. Finally, the sum of the second and fourth digits is twice the sum of the other 2 digits. What is the third digit of the number?
Topic: Digits

[1] 5
[2] 8
[3] 1
[4] 4