SOLUTION: 1. It takes Mom, Dad and Isabel two hours to shovel their driveway after a snow storm. If Dad worked alone, it would take him 4 hours to shovel the entire driveway by himself. If I

Question 1033196: 1. It takes Mom, Dad and Isabel two hours to shovel their driveway after a snow storm. If Dad worked alone, it would take him 4 hours to shovel the entire driveway by himself. If Isabel worked alone, it would take her twice as long as Dad. How long would it take Mom to shovel the driveway herself?
Answer by ikleyn(52802) (Show Source): You can put this solution on YOUR website!
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1. It takes Mom, Dad and Isabel two hours to shovel their driveway after a snow storm.
If Dad worked alone, it would take him 4 hours to shovel the entire driveway by himself.
If Isabel worked alone, it would take her twice as long as Dad.
How long would it take Mom to shovel the driveway herself?
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Dad's rate of work is  of the driveway per hour.

Isabel's rate of work is  of the driveway per hour.

Isabel's + Dad's combined rate of work is  =  of the driveway per hour.

Mom'w + Dad's + Isabel's combined rate of work is  of the driveway per hour.

Hence, Mom's rate of work is is  =  of the driveway per hour.

Can you now answer the question to the problem?

On joint-work problems see the lessons
    - Using Fractions to solve word problems on joint work,
    - Solving more complicated word problems on joint work,
    - Selected joint-work word problems from the archive
in this site.

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