Solve the Problem $5 \mathrm{mph}$ If a Boat Travels 82 Miles Downstream in the \mathrm{mph}

Multiple Choice

Solve the problem.
-The speed of a stream is $5 \mathrm{mph}$ . If a boat travels 82 miles downstream in the same time that it takes to travel 41 miles upstream, what is the speed of the boat in still water?

A) $18 \mathrm{mph}$
B) $17 \mathrm{mph}$
C) $15 \mathrm{mph}$
D) $10 \mathrm{mph}$