SOLUTION: A girl can rake the entire yard in 8 hours. When a boy does it alone, it takes him 9 hours. How long would it take them to rake the yard together? Round to the nearest minute.

Question 963127: A girl can rake the entire yard in 8 hours. When a boy does it alone, it takes him 9 hours. How long would it take them to rake the yard together? Round to the nearest minute.
Found 2 solutions by amarjeeth123, macston:
Answer by amarjeeth123(570) (Show Source): You can put this solution on YOUR website!
A girl can rake the entire yard in 8 hours.
In 1 hour she can rake 1/8th of the yard.
When a boy does it alone, it takes him 9 hours.
In 1 hour he can rake 1/9th of the yard.
When they work together in 1 hour they can rake (1/8+1/9) of the yard.
In 1 hour they can rake 17/72 of the yard.
Total time taken=72/17hours=254 minutes(approx.)
Answer by macston(5194) (Show Source): You can put this solution on YOUR website!
Girl=1yard/480min=1/480 yard/min=9/4320 yd/min
Boy=1 yard/540 min=1/540 yard/min=8/4320 yd/min
Together=9/4320 yd/min + 8/4320 yd/min=17/4320 yd min
1 yard/ (17/4320 yd/min)=254 minutes
ANSWER: Together they can rake the yard in 254 minutes.
RELATED QUESTIONS
When all the leaves have fallen, a girl can rake the entire yard in 8 hours. When a boy... (answered by ewatrrr)
when all the leaves have fallen, a girl can rake the entire yard in 6 hours. when a boy... (answered by richwmiller)
when leaves have fallen a girl can take the yard in entire 8 hours. when a boy does it... (answered by Alan3354)
Craig and Cara, working together, can rake the yard in 8 hours. Working alone, Cara... (answered by edjones)
Craig and Matt, working together can rake the yard in 8 hours. Working alone, Matt takes... (answered by josgarithmetic)
Pam and Cindy, working together, can rake The yard in 5 hours. working alone, Cindy takes (answered by richwmiller)
Jim and Shirley, working together, can rake the yard in 3 hours. Working alone, Shirley... (answered by lwsshak3,josgarithmetic)
If it takes Luke 3 hours to rake a yard, and Don 5 hours to rake the same yard, how long... (answered by Fombitz,Edwin McCravy)
Martha can rake leaves in her yard in 8 hours. Her brother can rake leaves in 4 hours.... (answered by Cromlix)