Question 613715
If it takes Bob 3 hours to paint a room and Linda 5 hours to paint a room, how long will it take them to paint the room together?
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let x=Hours Bob and Linda will take to paint the room together
Bob's work rate=1/3
Linda's work rate=1/5
Work rate working together=1/x
sum of individual work rates=work rate working together
1/3+1/5=1/x
x/3+x/5=1
LCD:15
5x+3x=15
8x=15
x=15/8
ans:
Hours Bob and Linda will take to paint the room together=15/8