Question 35175
  Jennifer is going to clean up her room. If her work rate of this job is 5/7 per hour, how long will it take her to clean her room? Your answer is supposed to have the form h hour and m minutes, where h and m are positive integers. Put h in the 1st box with the unit   hr, and put m in the 2nd box with the unit   min. 
 
Let "x" be the number of hours it takes her to clean her room.
Her rate multiplied by the amount of time to finish the job = 1 job done
By the way her rate means (5 jobs/ 7 hrs) or (5/7)job/hr.
EQUATION:
  rate*time = job
  [(5/7)job/hr][x hr] = 1job
 Multiply both side by 7/5 to get 
 x = (7/5) hrs.
(7/5) (60 minutes) = 84 minutes = 1 hr. and 24 minutes
Cheers,
Stan H.