SOLUTION: Sean mows his half of hte yard in 30 minutes. His brother takes 50 minutes. If they each had their own lawn mower and worked together, how long would the job take?

Question 185098: Sean mows his half of hte yard in 30 minutes. His brother takes 50 minutes. If they each had their own lawn mower and worked together, how long would the job take?
Found 2 solutions by stanbon, solver91311:
Answer by stanbon(75887) (Show Source): You can put this solution on YOUR website!
Sean mows his half of the yard in 30 minutes. His brother takes 50 minutes. If they each had their own lawn mower and worked together, how long would the job take?
-------------------------
Sean DATA:
time = 30 min/job ; rate = 1/30 job/min
--------------------------------------------
Brother DATA:
time = 50 min/job ; rate = 1/50 job/min
-------------------------
Together DATA:
time = x min/job ; rate = 1/x job/min
------------------------------
Equation:
rate + rate = together rate
1/30 + 1/50 = 1/x
To get rid of the denominators,
multiply thru by 150x to get:
5x + 3x = 150
8x = 150
x = 150/8 = 18 3/4 minutes (time to do the job together)
=============================================================
Cheers,
Stan H.

Answer by solver91311(24713) (Show Source): You can put this solution on YOUR website!

If A can do a job in x time periods, then A can do of the job in 1 time period. Likewise, if B can do the same job in y time periods, then B can do of the job in 1 time period.

So, working together, they can do

of the job in 1 time period.

Therefore, they can do the whole job in:

time periods.

Just substitute your given time values and do the arithmetic.

John

RELATED QUESTIONS
LeBron mows yards. For each yard he charges $5.50 for the use of his mower and $3.50 for... (answered by josgarithmetic)
Timothy can mow his lawn in 40 minutes, but his brother Shamus needs only 30 minutes to... (answered by nerdybill)
Randy and his sister agreed that they would each mow one-half of the lawn. The lawn is a... (answered by ankor@dixie-net.com)
It takes a boy 90 minutes to mow his father's yard but his sister can do it in 60... (answered by advanced_Learner,Theo)
Cindy mows a lawn in 50 minutes. It takes Sara 40 minutes to mow the same lawn. How... (answered by angelicnwa)
Randy and his sister agreed that they would each mow one half of the lawn. The lawn is a... (answered by ankor@dixie-net.com)
Brian and his sister, Linda, agreed that they would each mow one-half of the lawn. The... (answered by stanbon)
Russ started to mow the lawn,a task that usually takes him 40 minutes.After he had been... (answered by ikleyn,richwmiller)
Juan can mow a lawn with a hand mower in 4 hours. His friend Pedro can mow the same lawn... (answered by FrankM)