Solve the problem.
-A boat traveled for $3 \mathrm{hr}$ with a 7 -mph current to reach a picnic area. The return trip against the same current took $6 \mathrm{hr}$. Find the speed of the boat in still water.
A) $49 \mathrm{mph}$
B) $21 \mathrm{mph}$
C) $28 \mathrm{mph}$
D) $84 \mathrm{mph}$

Question

Quizplus · Accepted Answer

The speed of the boat in still water can be found by setting up the equation $\frac{d}{s + 7} = 3$ and $\frac{d}{s - 7} = 6$, where $d$ is the distance, $s$ is the speed of the boat in still water, and 7 is the speed of the current. Solving these equations simultaneously, we find that $s = 21$ mph.

Solve the Problem 3hr3 \mathrm{hr}3hr With a 7 -Mph Current to Reach a Picnic Area

Solve the Problem $3 \mathrm{hr}$ With a 7 -Mph Current to Reach a Picnic Area