SOLUTION: Frank can cut his lawn in 4 1/2 hours, his wife can cut the same lawn in 4 hours, while their son tom can cut the lawn in 3 1/2 hours. how long would it take to cut the lawn if all

Algebra ->  Rate-of-work-word-problems -> SOLUTION: Frank can cut his lawn in 4 1/2 hours, his wife can cut the same lawn in 4 hours, while their son tom can cut the lawn in 3 1/2 hours. how long would it take to cut the lawn if all      Log On


   



Question 305608: Frank can cut his lawn in 4 1/2 hours, his wife can cut the same lawn in 4 hours, while their son tom can cut the lawn in 3 1/2 hours. how long would it take to cut the lawn if all three worked together?
Found 2 solutions by solver91311, richwmiller:
Answer by solver91311(24713) About Me  (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.

The above works just fine if you only have two people (things, whatever) doing the work. But your problem has three people working together.

Yep.



And then



You can do your own arithmetic.


John


Answer by richwmiller(17219) About Me  (Show Source):
You can put this solution on YOUR website!
x/4.5+x/4+x/3.5=1
x(2/9+1/4+2/7)=1
(191x)/252 = 1
x=252/191
x=1.31937
What family has three mowers?