Find the LCM of 12 and 15

Question

Find the LCM of 16 and 20

Answer 1

12 = 2*2*3
15 = 3 * 5
so we need
two 2s
a 3
and a 5
2*2*3*5 = 60

Answer 2

16 = 2*2*2*2
20 = 2*2*5
we need 4 twos and a five
16*5 = 80