What number does 3, 15, 5, and 9 go into evenly?
Well 3 and 5 go into 15 so you only need to worry about what 15 and 9 both go into.
15 = 3*5
9 = 3 *3
so 3*3*5 = 45 will be you answer
All multiples of 45 will work just fine :)
