What are the multiples that 30 and 36 have in common?

Answer 1

In order to find the common multiples of two numbers you first need to express them as the product of their prime factors:

30 = 2x3x5

36 = 2x2x3x3

The next step is to identify any common factors. In this case, both numbers have a 2 and a 3 as prime factors, so we can discard one of each. Take all the remaining prime factors (2, 2, 3, 3 and 5) and multiply them together to get the LCM:

2x2x3x3x5 = 180. To find other multiples that 30 and 36 have in common, you multiply this number by any integer (2, 3, 4...) Thus the first few common multiples of 30 and 36 are:

180, 360, 540, 720...