SOLUTION: there are 4 experienced movers who can complete the job in 3 hours, 6 inexperienced movers can complete the job in 4 hours, how long will it take for them to complete the job toget

Algebra ->  Rate-of-work-word-problems -> SOLUTION: there are 4 experienced movers who can complete the job in 3 hours, 6 inexperienced movers can complete the job in 4 hours, how long will it take for them to complete the job toget      Log On


   



Question 929653: there are 4 experienced movers who can complete the job in 3 hours, 6 inexperienced movers can complete the job in 4 hours, how long will it take for them to complete the job together?
Answer by LinnW(1048) About Me  (Show Source):
You can put this solution on YOUR website!
set e = rate of an experienced mover in jobs per hour
i = rate of an inexperienced in jobs per hour
We have 4e * 3 hours = 1 job
and 6i * 4 hours = 1 job
First work with 4e * 3 = 1
12e = 1
e = 1/12 jobs per hour
Now work 6i * 4 = 1
24e = 1
i = 1/24
So for all working together
(6(1/24) + 4(1/12))y = 1
( 1/4 + 1/3 ) y = 1
( 3/12 + 4/12 )y = 1
( 7/12 )y = 1
multiply each side by 12/7
y = 12/7 hours = 1 5/7 hours