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?

Click here to see ALL problems on Money Word Problems

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