Playing With Numbers – Class 8/MCQ

CBSE CLASS 8 MATHEMATICS-
Playing With Numbers – Chapter 16 / MCQ
Multiple Choice Questions.

Choose the correct answer from the options given below:

1. Numbers can be written in general form. Thus a two digit number ab will be written as ab = —————
A. 10a + b
B. 10b + a
C. a + b
2. A three digit number abc made up of digits a, b and c is written as abc = ——
A. a + 10b + 100c
B. 100a + 10b + c
C. 1000a + 100b + 10c
3. A number is divisible by 10 when its one’s digit is ————–
A. Zero
B. One
C. Two
4. If the ones digit of a number is 0 or 5, then it is divisible by —————
A. 2
B. 5
C. 10
5. A number N is divisible by 9 if the sum of its digits is divisible by ———–
A. 6
B. 9
C. 12
6. If the three digit number 24x is divisible by 9, what is the value of x?
A. 3
B. 6
C.9
7. Which of the following numbers are not divisible by 9.
A. 108
B. 432
C. 616
8. Which of the following numbers are not divisible by 3?
A. 108
B. 432
C. 616
9. If 21y5 is a multiple of 9, where y is a digit, what is the value of y?
A. 1
B. 2
C. 3
10. What is the general form of the four digit number abcd?
A. 1000a + 100b + 10c + d
B. a + 10b + 100c + 1000d
C. 10a + 100b + 1000c + d

ANSWERS;

1. 10a + b

2. 100a + 10b + c

3. Zero

4. 5

5. 9

6. 3
(Since 24x is divisible by 9, sum of its digits = 2 + 4 + x should be divisible by 9.
i.e. 6 + x should be divisible by 9.
This is possible when 6+x =9 or 18……
But, since x is a digit, therefore 6+x =9
So x = 9-6 = 3)

7. 616

8. 616

9. 1
(Since 21y5 is divisible by 9, sum of its digits = 2+1+y+5 should be divisible by 9.
i.e. 8 + y should be divisible by 9.
This is possible when 8+y = 9.
But since y is a digit, therefore y= 9-8 = 1)

10. 1000a + 100b + 10c + d