Question

The number 123456 is not divisible by ________

• A. 2
• B. 3
• C. 6
• D. All of these

Answer 1

The correct option is A

2

1) Test for 2:- ends with 6.
$⟹$ 123456 is divisible by 2 [If a number ends with 0, 2, 4, 6 or 8, it is divisible by 2]

2) Test for 3:- sum of digits = 1 + 2 + 3 + 4 + 5 + 6 = 21, which is divisible by 3.
$⟹$ 123456 is divisible by 3 [If sum of digits of a number is divisible by 3, the number is divisible by 3]

3)Test for 5:- doesn't end with 5 or 0.
$⟹$ 123456 is not divisible by 5 [If a number is divisible by 5, it ends with 5 or 0]

4)Test for 6:- 123456 is divisible by 2 and 3.
$⟹$ 123456 is divisible by 6. [If a number is divisible by 2 and 3, it is divisible by 6]