SOLUTION: 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?

Algebra ->  Rate-of-work-word-problems -> SOLUTION: 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?      Log On


   

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?
Found 2 solutions by ewatrrr, lwsshak3:
Answer by ewatrrr(24785) About Me  (Show Source):
You can put this solution on YOUR website!
 

Hi, 

Bob takes 3 hours to paint a room  and Linda 5 hours to paint a room

Let x represent the time it would take them together

PER hour is KEY

 1/3 + 1/5 = 1/x        |Multiplying thru by 15x so as all denominators = 1

   5x + 3x = 15

     8x = 15

      x = 15/8 hrs  or 2 7/8 hrs

Answer by lwsshak3(11628) About Me  (Show Source):
You can put this solution on YOUR website!
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?
**
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