SOLUTION: if person A can paint a house in 4 hours, and person B can paint the same house in 7 hours... how much time would it take for A and B to paint the same house working together?

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Question 554834: if person A can paint a house in 4 hours, and person B can paint the same house in 7 hours... how much time would it take for A and B to paint the same house working together?
Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
Add their rates of painting to get their
rate working together
A's rate: ( 1 house ) / ( 4 hours )
B's rate: ( 1 house ) / ( 7 hours )
Let their time working together = +t+
+1%2F4+%2B+1%2F7+=+1%2Ft+
Multiply both sides by +28t+
+7t+%2B+4t+=+28+
+11t+=+28+
+t+=+2.545+
+.5454%2A60+=+32.73+
Working together, they paint the house in 2 hrs and 33 min