Question

The local library does children's plays every 18 days, and storybook readings every 5 days. If they both start on the first day of the month, how many days will it take for them to happen on the same day again?

Answer 1

Answer: 90 days

Step-by-step explanation:

Given

Children's play occurs every 18 days

Storybook readings occur every 5 days

Suppose after the first day both will occur after x days

$\Rightarrow x=\text{LCM of }18\ \text{and}\ 5\\\Rightarrow \text{LCM}(5,18)=90\ \text{days}$

It will take 90 days  to happen again