Question

Working alone, Carlos can oil the lanes in a

bowling alley in five hours. Jenny can oil
the same lanes in nine hours. If they worked
together how long would it take them?

Answer 1

3.21 hrs.

Explanation:

Carlos oils all lanes/5 hrs. = 1/5 of the lanes/hr. Jenny oils all lanes/9 hrs. =1/9 lanes per hour. To do all lanes 1/0.311=3.21 hrs. ANSWER: Together it takes Carlos and Jenny 3.21 hours to oil all the lanes!