SOLUTION: David can paint a bedroom in 1.5 hr. Jay can paint the same bedroom in 2.75 hr. How long will it take them working together, to paint the room?

Question 694593: David can paint a bedroom in 1.5 hr. Jay can paint the same bedroom in 2.75 hr. How long will it take them working together, to paint the room?
Answer by Edwin McCravy(20056) (Show Source): You can put this solution on YOUR website!

David can paint 1 bedroom in 1.5 hr. Therefore David's painting rate is



Jay can paint 1 bedroom in 2.75 hr. Therefore Jay's painting rate is



Suppose that together they can paint 1 bedroom in x hr.  Then their combined
painting rate is



The sum of their painting rates must equal to their combined painting rate.
--[Just as in other problems when we find the sum of a boat's rate and the rate of the current]--

          

                  

Solve that by multiplying through by the LCD of 33x and you get x = hr 
or about 0.97 hr or about 58 minutes.

Edwin

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