Which rate is greater? 18 pages in 36 minutes or 20 pages in 30 minutes. explain your resoning

The second example is a greater rate of reading. 

In order to come to that conclusion, I didn't do any figuring, ciphering,
numerating, or calculating of any kind.  I just sat there and looked at
the question.  I noticed that the second example is more pages than
the first one, but done in less time than the first one.  So I know that
it must be a greater rate of cranking out the pages.

Just look outside and then you’ll see where the awnser is