Here we are given how much work is done in a fix time interval
then they ask to find the rate of doing the work .
in such problem we can find the rate of doing a work by using the formula :
amount of work done
--------------------------------------------------- = work done in unit time
Time taken to do that amount of work
In 40 minutes number of pages she reads = 50
In 1 minutes number of pages she would be reading = 50 /40
= 5/4 page
Answer 5/4 page .