Question

If 74A0BB0 is a seven digit number that is divisible by 72.Then find A and B very fast

Answer 1

I'm not sure though but, I can suggest you an approach. if this no. is divisible by 72 then it must be divisible by 9 & 8. check for conditions of divisibility from these, where you will get two equations & then solve for a & b. if this no. is divisible by 9 then, the sum of its digits must be divisible by 9 or by its multiple, also, for 8 it's last 3 digits should be divisible by 8.