SOLUTION: If i takes painter a 7 hours to paint a room and painter a & painter b 5 hours to paint the same room. How long would it take painter b by himself?

Question 981179: If i takes painter a 7 hours to paint a room and painter a & painter b 5 hours to paint the same room. How long would it take painter b by himself?
Answer by Boreal(15235) (Show Source): You can put this solution on YOUR website!
Do what each can do in an hour.
(1/7) for painter A.
(1/7) + (1/x)=(1/5) , which means in 1 hour, they paint 1/5 of the room
common denominator is 35x
5x+35=7x
2x=35
x=17.5 hours for painter B.
Check
(1/7) + (1/17.5)=(17.5 +7)/122.5 = 24.5/122.5

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