SOLUTION: Stefan could wash the cars by himself in 6 hours and Misha could wash the cars by himself in 5 hours. Stefan starts washing the cars by himself, but he needs to go to his football

Algebra.Com
Question 884374: Stefan could wash the cars by himself in 6 hours and Misha could wash the cars by himself in 5 hours. Stefan starts washing the cars by himself, but he needs to go to his football game after 2.5 hours. Misha continues the task. How long did it take Misha to finish washing the cars?
Answer by josmiceli(19441)   (Show Source): You can put this solution on YOUR website!
What fraction of the cars did Stefan wash in 2.5 hrs?
His rate of washing is:
( 1 job ) / ( 6 hrs ) =
Note that I call washing all the cars 1 job
------------------------------------
Let = fraction of cars he washes in 2.5 hrs

Multiply both sides by



--------------
So, Stefan washes 5/12 of the cars in 2.5 hrs. That
means there are 7/12 of the cars left to wash
-----------------------------------------
Misha takes over by himself. His rate is:
( 1 job ) / ( 5 hrs ) =
Let = time in hrs for him to finish washing cars
by himself


Multiply both sides by



------------------
How many minutes is hrs?

---------------------
Misha takes 2 hrs and 55 min to finish washing the cars

RELATED QUESTIONS

Wendy can wash a car twice as fast as Jason. When they work together, Wendy and Jason can (answered by josgarithmetic)
If a guy can wash a car in 6 minutes by himself and a different guy can wash the car in 8 (answered by Edwin McCravy)
julio and james can wash 5 cars in 3 hours. At the same rate, how many cars can they wash (answered by josmiceli)
Art club held a car wash. They estimated that each team could wash 5 cars per hour. If... (answered by josmiceli)
Four employees can wash 20 cars in five hours. How long will it take 5 employees to wash... (answered by ewatrrr)
John can wash 7 cars in 3 hours and Kevin can wash 21 cars in 12 hours. If they work... (answered by nerdybill)
Please help me solve this problem. If it takes a car wash 2 hours and 10 minutes to... (answered by stanbon)
tom and jon together can wash their car in 12 minutes it takes tom 18 minutes alone to... (answered by ewatrrr)
Bobo can wash the car in 36 minutes by himself. When his brother Otto helps, they finish (answered by stanbon)