A number that is divisible by 5 is one that ends with either a 5 or 0. To find a number that is divisible by 3 add up the digits and if they are divisible by 3, the number also is. That rules c out because it doesn't end with a 5 or 0. 130 and 325 won't work because they are not divisible by 3. The answer would be 2040.
