Question

Brad and Stella volunteer to help at the party. Brad volunteers at the prize table and Stella

volunteers at the refreshment table. Both workstations allow volunteers a short break, but at
different intervals. The prize table allows volunteers a short break every 20 minutes, but the
refreshment table allows a short break only every 30 minutes. If the party is scheduled to start
at 2:00 pm and Brad and Stella both start working then, what is the first time that they will be
on break together? Show all work.

Answer 1

They will be able to have their break together in 60 minutes.

Explanation:

You will have to find the least common multiple (LCM) between 20 and 30.

The prime factorization of 20 is: 2 x 2 x 5

The prime factorization of 30 is: 2 x 3 x 5

Eliminate the duplicate factors of the two lists, then multiply them once with the remaining factors of the lists to get lcm(20,20) = 60