Question

Using divisibility tests, solve the problem:
Jason bought a new bike for $678, and he plans to make equal monthly payments to pay for it. Can he pay off the bike in 3 equal payments?

Answer 1

To test if a number is divisible by 3, you just need to add the digits up, and if the resulting number is divisible by 3, then the original number is divisible by 3, too.
So if 6+7+8 is divisible by 3, then 678 is also divisible by 3.