Question

If 31z5 is a multiple of 3, where z is a digit, what might be the values of z?​

Answer 1

Answer:

∵ 31 z5 is divisible by 3. ∴ ( 9 + z) must be divisible by 3. since, z is a digit. ∴ Possible values of z are 0, 3, 6 or 9.