Answer: 4/5 book per hour
Step-by-step explanation: in this question, we are to rewrite (2/5)/(1/2) as unit rate.
To write this as a unit rate, what we need to do is to divide 2/5 by 1/2.
That means 2/5 divided by 1/2
Removing the division and replacing with multiplication will give 2/5 * 2/1 = 4/5 books/hour