SOLUTION: bj can overhaul a boat's engine in 30 hours. his apprentice takes 60 hours to do the same job. how long would it take them to work together assuming no gain or loss in effeincy

Algebra ->  Rate-of-work-word-problems -> SOLUTION: bj can overhaul a boat's engine in 30 hours. his apprentice takes 60 hours to do the same job. how long would it take them to work together assuming no gain or loss in effeincy       Log On


   

Question 932174: bj can overhaul a boat's engine in 30 hours. his apprentice takes 60 hours to do the same job. how long would it take them to work together assuming no gain or loss in effeincy
Answer by richwmiller(17219) About Me  (Show Source):
You can put this solution on YOUR website!
1/a+1/b=1/x
1/30+1/60=1/x
60/1800+30/1800=1/x
90/1800=1/x
x=1800/90
x=20 hours working together
check
x/a+x/b=1
x/30+x/60=1
20/30+20/60=1
0.66666667+0.33333333=1
1=1
ok
codewt