since a number is divisible by 2 and 3 and 5 it can be written as 2*3*5*x=num where x is a natural number
a number is only divisible by a number if they share the same prime divisors so the numbers that will always be divisible by that number are:2,3,5,2*3:6,2*5:10,3*5:15,2*3*5:30 C)30 which is the correct answer
