Question

The number 123456 is not divisible by

• A. 2
• B. 3
• C. 6
• D. 9

Answer 1

The correct option is D

9

1) Divisibility by 2
123456 ends with 6 so it is divisible by 2
[If a number ends with 0, 2, 4, 6 or 8, it is divisible by 2.]

2) Divisibility by 3
Sum of digits = 1 + 2 + 3 + 4 + 5 + 6 = 21
21 is divisible by 3. So, 123456 is divisible by 3.
[If sum of digits of a number is divisible by 3, the number is divisible by 3.]

3) Divisibility by 6
123456 is divisible by 2 and 3. So 123456 is divisible by 6.
[If a number is divisible by 2 and 3, it is divisible by 6.]

4) Divisibility by 9
Sum of the digits = 21 which is not divisible by 9, so the number is not divisible by 9.
[If the sum of digits of a number is divisible by 9, then the number is divisible by 9.]