Find the least common denominator of 3/20 and 9/8

40

Step-by-step explanation:

To find the least common denominator, you find the least common multiples of the denominators, which in this case is 20 and 8.

Tower method:

Start: |20, 8

4 |20, 8 -> 4 is a factor that 20 and 8 have in common

  5,   2   -> 20/4 = 5, 8/4 = 2, those numbers do not have a common factor.

4 * 5 * 2 = 40.

The fractions with 40 as its denominator is 6/40 and 45/40.