Question

 Donna and Phyllis are reviewing for a math final. They have 150 pages to cover. Donna can review 37 pages an hour, but Phyllis can only go 2/3 as fast as Donna. About how long does it take each girl to finish?

Answer 1

Donna: 37 pages per hour.  There are 150 pages.
Time: 150 pages  / (37 pages/hour)
= 150/37 hours
= 4 hours 3 1/2 min. (approx.)

Phyllis: (2/3)*37 pages per hour.  There are 150 pages.
Time: 150 pages / ((2/3)*37 pages / hour )
= 150*3/(2*37) hours
= 225/37 hours
= 6 hours 5 minutes (approx.)