How do you get the LCM of 12 15 and 20?

Answer 1

To find the LCM of 3 numbers you first need to split them into their prime factors:

12 = 2x2x3

15 = 3x5

20 = 2x2x5

The next step is to identify any common factors. In this case, two numbers have 3, so we can discard one of these. Two numbers have two 2s, so we can discard 2 of these. Two numbers also have a 5, so we can discard one of these. That leaves us with 2, 2, 3, 5 as the prime factors. Multiplying these together gives:

2x2x3x5 = 60. And therefore 60 is the LCM of 12, 15 and 20.