Question

Richard can read 1/4 of a book in 2/5 of an hour. At this rate, how much can Richard read in one hour?

Answer 1

0.375 of a book in an hour

Answer 2

if he reads 1/4 of a book in 2/5 of an hour
he will read 0.625 of a book in an hour, or 5/8 of a book.
solve it with a proportion
1/4 of a book : 2/5h = X : 1h
X = (1/4)/(2/5) = 5/8