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)   (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

 

RELATED QUESTIONS

It takes Sue 3 hours to paint a room and it takes Joe 5 hours to paint the same room.  If  (answered by checkley77)

Nicole can paint a room in six hours, Alexandra can paint a room in 5 hours, and Liana... (answered by josmiceli)

Bob can paint a room in 3 hours working alone. It takes Barbara 5 hours to paint the same  (answered by ikleyn)

Sam and Pat are painting a room. Sam can paint the room in 3 hours, Pat can paint the... (answered by stanbon)

If Bill takes 3 hours to paint a room and James takes 5 hours to paint a room, how long... (answered by ikleyn)

it takes Mary 4 hours to paint a room, John 5 hours to paint the room, and Jacob 6 hours... (answered by ikleyn)

David can paint a room in 5 hours.  Patti can paint a room in 7 hours.  How long will it... (answered by richwmiller)

if john can paint a room in 2 hours while peter takes 6 hours . how long will it take... (answered by ewatrrr,richwmiller)

sally can paint a room in 6 hours, it takes steve 3 hours to paint the same room. how... (answered by josmiceli)