Question

Paula and Karen are playing a game. Paula counts by 4s. Karen counts by 5s. They try to pace the counting so they will say the first common number together. What is the first number they both say together?

Answer 1

20

Explanation:

We are to determine the lowest common multiple of 4 and 5

the first six multiple of 4 are = 4, 8, 12, 16, 20, 24

the first six multiple of 5 are = 5, 10, 15, 20, 25

the multiple they both have in common is 20