SOLUTION: John can paint his room in 5 hours; Toby can paint the same room in 8 hours. How long will it take if they work together?

Question 910318: John can paint his room in 5 hours; Toby can paint the same room in 8 hours. How long will it take if they work together?
Found 2 solutions by ewatrrr, josmiceli:
Answer by ewatrrr(24785) (Show Source): You can put this solution on YOUR website!
|Multiplying thru by 35x so as all denominators = 1
7x + 5x = 35
12x = 35
x = 35/12 0r 2 11/12 hr 0r 2hr 55min
Answer by josmiceli(19441) (Show Source): You can put this solution on YOUR website!
Add their rates of working to get
their rate working together
-------------------------
John's rate:
( 1 room ) / ( 5 hrs )
Toby's rate:
( 1 room ) / ( 8 hrs )
-----------------
Let their rate working together
= ( 1 room ) / ( t hrs )

Multiply both sides by

It will take them 3.077 hrs, or about
3 hrs 5 min working together
-------------------------
check answer:

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