Question

The six digit number 54321X is divisible by 9 where X is a single digit whole number. Find A

Answer 1

A number is divisible by 9, when the sum of its digits is divisible by 9. Here, 5 + 4 + 3 + 2 + 1 + A = 15 + A should be divisible by 9.

Therefore, A = 3 gives 15+ 3 = 18 as the sum of digits, which is divisible by 9. So, answer is 3