Question

Jill takes 2 hours to paint a room, Jim takes 3 hours to paint a room. How long (in minutes) will it take both of them to paint a room

Answer 1

Jill will take 120 minutes to paint a room

Jim will take 180 minutes to paint a room

All together Jim and Jill will take 200 minutes to paint a room

Answer 2

Answer:

  72 minutes

Step-by-step explanation:

The sum of the rates of work in rooms per hour is ...

  Jill's rate + Jim's rate

  = (1/2 room/hour) +(1/3 room/hour) = (3/6 +2/6 room/hour) = 5/6 room/hour

__

Then the combined rate in hours per room is ...

  1/(5/6 room/hour) = 6/5 hours/room = (6/5 hours/room)(60 minutes/hour)

  = 72 minutes per room

Jill and Jim can paint the room in 72 minutes when they work together.