SOLUTION: Sara can clean the apartment in six hours. It takes Lucy twelve hours to clean the same apartment. If Sara and Lucy work together cleaning the apartment, how many hours will it tak

Algebra ->  Rate-of-work-word-problems -> SOLUTION: Sara can clean the apartment in six hours. It takes Lucy twelve hours to clean the same apartment. If Sara and Lucy work together cleaning the apartment, how many hours will it tak      Log On


   



Question 1000739: Sara can clean the apartment in six hours. It takes Lucy twelve hours to clean the same apartment. If Sara and Lucy work together cleaning the apartment, how many hours will it take them?
Answer by fractalier(6550) About Me  (Show Source):
You can put this solution on YOUR website!
The setup looks like this
t/6 + t/12 = 1
where t is the time they work together, and 1 represents one job.
Multiply by twelve and get
2t + t = 12
3t = 12
t = 4 hours