First you should work out how much he read in one minute. To do that you divide the number of pages(18) by the time (40 mins).
18/40 = 0.45
Then multiply this number by 60 minutes to get the unit rate per hour.
0.45 x 60 = 27.
Gordon reads 27 pages per hour.
Hope This Helps You!
Good Luck Studying :)
