Question

If we subtract the sum of digits of any two digit number from the number we get a multiple of :

• A. 3
• B. 5
• C. 9
• D. 7

Answer 1

Answer: (A), (C)

The correct options are
A

3

C

9

Let the Digit in unit's place be m and that at ten's place be n

General form of the number will be 10n + m

Sum of the digits = n + m

Now, when we do the subtraction of the sum of digits from the number we get :

10n + m - n - m = 9n

$\therefore$ It is always divisible by 9 and

$\therefore$ it will also be divisible by 3