Answer:
It will take him 20 days to read a 300-page book.
Explanation:
Given:
Stephen read a 90-page book in 6 days.
If he continues reading at that rate.
Now, to find the time it will take him to read a 300-page book.
So, we solve using unitary method:
If, Stephen read 90 pages in 6 days.
So, Stephen read 1 page in =
days.
Thus, Stephen read 300 page in =



Therefore, it will take him 20 days to read a 300-page book.