Solve the Problem $5 \mathrm{hr}$ B) $1 \mathrm{hr}$ C) $4 \mathrm{hr}$ D) $6 \mathrm{hr}$

Multiple Choice

Solve the problem.
-From a point on a river, two boats are driven in opposite directions, one at 8 miles per hour and the other at 10 miles per hour. In how many hours will they be 72 miles apart?

A) $5 \mathrm{hr}$
B) $1 \mathrm{hr}$
C) $4 \mathrm{hr}$
D) $6 \mathrm{hr}$