Greta read a 900 pages book in 15 days, reading for 5 hours every day. what was her reading rate in pages per minute?

We are going to set up a couple of fractions and multiply them together to find her reading rate per minute. 



To put into context what those fractions are:
 
She reads 900 pages in 15 days. 5 hours per day. There are 60 minutes in an hour. The days and hours cancel out since they are in both the numerator and denominator, leaving you with pages per min.

This leaves you with:

which simplifies to  which equals 0.2 or 1/5. 

Greta reads 1/5 of a page per minute or 0.2 pages per minute.