My question is about unit rates

Question

A construction company can remove 5 1/4 metric tons of dirt from a construction site in 4 1/2 hours.

What is the unit rate in metric tons per hour?

Write your answer as a fraction or a mixed number in simplest form.

Answer 1

5 1/4 divided by 4 1/2

= 21/4 divided by 9/2

= (21/4)(2/9) = (7)/6

= 1 1/6 ton per hour