SOLUTION: Marge could clean the house in 5 hours. Lisa could clean it in 3 hours. How long will it take the both of them to clean the house?

Algebra ->  Rate-of-work-word-problems -> SOLUTION: Marge could clean the house in 5 hours. Lisa could clean it in 3 hours. How long will it take the both of them to clean the house?      Log On


   

Question 860845: Marge could clean the house in 5 hours.
Lisa could clean it in 3 hours.
How long will it take the both of them to clean the house?
Answer by ben720(159) About Me  (Show Source):
You can put this solution on YOUR website!
Marge's rate is 1 job/5 hours
Lisa's rate is 1 job/ 3 hours
Together their rate is 1/5+1/3
1%2F5%2B1%2F3
Find the least common denominator, which is 15
3%2F15%2B5%2F15
8%2F15
Together, it will take them 8%2F15 of an hour.