Question

7.

Charlie and Dasha are roommates, and
they have a dog. If neither of them is
home, they hire someone to watch the
dog. Charlie must go on business trips
every 6 months, while Dasha must go on
business trips every 9 months. If they
both just got back from business trips,
how many months will it be before they
need to hire someone to look after the
dog again?

Explain your answer.

Answer 1

Answer: 18 months

Explanation:

If both of them aren't at home, then they hire someone to look after the dog. However, if Charlie is on a trip and Dasha isn't, they don't. So they would need to be at business trips at the same time and that means they will hire someone to look after the dog. So we find the LCM of 6 and 9 which is 18 months.

Answer 2

they wont need to hire someone for nine months.

Charlie will be gone in 6 months, while Dash has 3 more months after til she leaves.