SOLUTION: Working together, Jessica and Jill can install a new deck in 9 hours. Had she done it alone it would have taken Jill 21 hours.
How long would it take Jessica to do it alone?
Algebra ->
Rate-of-work-word-problems
-> SOLUTION: Working together, Jessica and Jill can install a new deck in 9 hours. Had she done it alone it would have taken Jill 21 hours.
How long would it take Jessica to do it alone?
Log On
Question 1180590: Working together, Jessica and Jill can install a new deck in 9 hours. Had she done it alone it would have taken Jill 21 hours.
How long would it take Jessica to do it alone? Answer by ikleyn(52818) (Show Source):
You can put this solution on YOUR website! .
Working together, Jessica and Jill can install a new deck in 9 hours.
Had she done it alone it would have taken Jill 21 hours.
How long would it take Jessica to do it alone?
~~~~~~~~~~~~~~~
Their combined rate of work is of the job per hour.
Jill's individual rate of work is of the job per hour.
Hence, Jessica's individual rate of work is the difference
- = - = = = =
of the job per hour.
It means that Jessica can complete the job in = 15 hours = 15 hours and 45 minutes. ANSWER
