SOLUTION: Ted can mow a lawn in 5 hours while eliot can mow the same lawn in 8 hours. How long will it take them to mow the lawn if they work together, but ted only mows for 2 hours?

Algebra ->  Rate-of-work-word-problems -> SOLUTION: Ted can mow a lawn in 5 hours while eliot can mow the same lawn in 8 hours. How long will it take them to mow the lawn if they work together, but ted only mows for 2 hours?      Log On


   



Question 625109: Ted can mow a lawn in 5 hours while eliot can mow the same lawn in 8 hours. How long will it take them to mow the lawn if they work together, but ted only mows for 2 hours?
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
They work together for 2 hrs
How much of the lawn do they mow working together?
Add their rates of mowing
Ted's rate:
( 1 lawn / 5 hrs )
Eliot's rate:
( 1 lawn / 8 hrs )
Mowing together:
( some part of the lawn / 2 hrs )
+1%2F5+%2B+1%2F8+=+x%2F2+
Multiply both sides by +40+
+8+%2B+5++=+20x+
+20x+=+13+
+x+=+13%2F20+
There is +1+-+13%2F20+=+7%2F20+ of the lawn left
to be mowed by Eliot alone
If he can mow ( 1 lawn / 8 hrs ),
he can mow +7%2F20+ of a lawn in +%287%2F20%29%2A8+=+2.8+ hrs
So, the whole lawn got mowed in +2+%2B+2.8+=+4.8+ hrs