SOLUTION: Jonh fixes 5 cars in 6 hours. It takes Mary 1 hour longer to fix 5 cars on her own than when she fixes with John. Together, how many hours does it take John and Mary to fix 5 cars?

Algebra ->  Rate-of-work-word-problems -> SOLUTION: Jonh fixes 5 cars in 6 hours. It takes Mary 1 hour longer to fix 5 cars on her own than when she fixes with John. Together, how many hours does it take John and Mary to fix 5 cars?      Log On


   

Question 1054652: Jonh fixes 5 cars in 6 hours. It takes Mary 1 hour longer to fix 5 cars on her own than when she fixes with John. Together, how many hours does it take John and Mary to fix 5 cars?
Answer by Fombitz(32388) About Me  (Show Source):
You can put this solution on YOUR website!
Find John's rate.
R%5BJ%5D%2A6=5
R%5BJ%5D=5%2F6
Find Mary's rate.
R%5BM%5D%2A7=5
R%5BM%5D=5%2F7
So together,
%28R%5BJ%5D%2BR%5BM%5D%29t=5
t=5%2F%285%2F6%2B5%2F7%29=%285%286%29%287%29%29%2F%285%2A7%2B5%2A6%29=210%2F67
or approximately 3.13 days