SOLUTION: A painter can paint a room alone in five hours. An assistant can paint the room alone in eight hours. if they work together for one half hour how long will it take the assistant t

Algebra ->  Rate-of-work-word-problems -> SOLUTION: A painter can paint a room alone in five hours. An assistant can paint the room alone in eight hours. if they work together for one half hour how long will it take the assistant t      Log On


   



Question 973048: A painter can paint a room alone in five hours. An assistant can paint the room alone in eight hours. if they work together for one half hour how long will it take the assistant to finish the job?
Answer by macston(5194) About Me  (Show Source):
You can put this solution on YOUR website!
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Painter: 1 room/5 hours=1/5 room/hr
Assistant: 1 room/8 hours=1/8 room/hr
In 1/2 hour, the painter paints 1/10 of the room and the assistant paints 1/16 of the room. 1/10+1/16=8/80+5/80=13/80. 13/80 has been painted leaving 1-13/80=67/80 to paint. The assistant paints 1/8 room per hour (10/80 room per hour) so to paint 67/80 room takes (67/80)/(10/80)=6.7 hours
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ANSWER: It takes the assistant 6.7 hours to finish the room.