SOLUTION: Mr. Brown painted two rooms in his house this past summer in 9 hours. Mr. Cook came over and helped him paint; the two of them worked together and painted another two rooms in 4 ho

Algebra ->  Rate-of-work-word-problems -> SOLUTION: Mr. Brown painted two rooms in his house this past summer in 9 hours. Mr. Cook came over and helped him paint; the two of them worked together and painted another two rooms in 4 ho      Log On


   



Question 403153: Mr. Brown painted two rooms in his house this past summer in 9 hours. Mr. Cook came over and helped him paint; the two of them worked together and painted another two rooms in 4 hours. How long would it have taken Mr. Cook to do the work, if he had done it himself?
Answer by scott8148(6628) About Me  (Show Source):
You can put this solution on YOUR website!
in the 4 hr that they worked together, Mr Brown painted 4/9 of the rooms
___ this means that Mr Cook painted 5/9 of the rooms in 4 hr

to do the whole (9/9) alone would take Mr Cook [4 / (5/9)] or [(4 * 9) / 5] hr