What two pair of numbers have a least common multiple of 105?

Answer 1

The prime factors of 105 are 5, 3 and 7. So to work out which two numbers have 105 as an LCM, we just have to share these factors between the two numbers, and add in any duplicates we want. For instance:

5x3 = 15

3x7 = 21

So 15 and 21 have a LCM of 105.

7x5 = 35

3x5 = 15

So 35 and 15 have a LCM of 105.

And so on.