SOLUTION: It takes Ralph 10 hours to paint a fence alone. Lisa can do the same job in 14 hours. If Ralph paints alone for 30 minutes before Lisa begins helping, how long must they work toget
Algebra ->
Rate-of-work-word-problems
-> SOLUTION: It takes Ralph 10 hours to paint a fence alone. Lisa can do the same job in 14 hours. If Ralph paints alone for 30 minutes before Lisa begins helping, how long must they work toget
Log On
Question 906390: It takes Ralph 10 hours to paint a fence alone. Lisa can do the same job in 14 hours. If Ralph paints alone for 30 minutes before Lisa begins helping, how long must they work together to finish painting the fence? Give your answer as a simplified fraction Answer by richwmiller(17219) (Show Source):
You can put this solution on YOUR website! x/a+x/b=1
.5/10+x/10+x/14=1
3.5/70+7x/70+5x/70=1
12x/70=66.5/70
12x=66.5
x=66.5/12
x=5 6.5/12
or
x=5.5417 hrs
5 hr 32 minutes 30.12 seconds
if they had started together it would be x=5.83 hours
