Question

Describe and correct the error finding the LCM.

10 = 2 x 5
15 = 3 x 5

LCM = 5

Answer 1

The least common multiple is the product of all the factors that appear. Thus, the LCM of 10 and 15 is:

2 x 3 x 5

The 5 appears in both numbers, so there is no need to multiply it twice.

The error in the example is that 5 is the GCF not the LCM.