B. For all 3 to work together, they can paint 1 room per hour. C. John can paint a room at 1/4 of a room per hour. Rick can paint a room at 1/5 of a room per hour. Together they can paint a room at a rate of 9/20 of rooms per hour. D. 1 = 1/4j + 1/5r + 11/20m (john, rick, molli) E. The least common denominator is 20 F. 1 = 1/4(0) + 1/5(0) + 11/20x 1 = 0 + 0 + 11/20x 1 = 11/20x x = 1/(11/20) x = 1 9/11 It will take Molli 1 hour and 49 minutes (60 x 9/11) to paint the room alone.
11 hours and 15 minutes because doing 2.25, which is equal to 2 hours and 15 minutes, times 5 you end up getting 11.25, and converting that to time you get 11 hours and 15 minutes.
