SOLUTION: rebecca can paint a room in 9 hours. Ryan can paint the same room in 8 hours. How long does it take for both rebecca and ryan to paint the room if they are working together

Algebra ->  Rate-of-work-word-problems -> SOLUTION: rebecca can paint a room in 9 hours. Ryan can paint the same room in 8 hours. How long does it take for both rebecca and ryan to paint the room if they are working together       Log On


   

Question 904190: rebecca can paint a room in 9 hours. Ryan can paint the same room in 8 hours. How long does it take for both rebecca and ryan to paint the room if they are working together
Answer by Alan3354(69443) About Me  (Show Source):
You can put this solution on YOUR website!
rebecca can paint a room in 9 hours. Ryan can paint the same room in 8 hours. How long does it take for both rebecca and ryan to paint the room if they are working together
-----------------------
Reb paints 1/9 of the room per hour.
Ryan paints 1/8 of the room per hour.
Together, they paint 1/8 + 1/9 = 17/72 room per hour
--> 72/17 hours/room
----------------
Here's a shortcut:
It's 8*9/(8+9) = 72/17