Solve the problem.
-A boat goes 480 miles downstream in the same time it can go 420 miles upstream. The speed of the current is 8 miles per hour. Find the speed of the boat in still water.
A) $112 \mathrm{mph}$
B) $128 \mathrm{mph}$
C) $120 \mathrm{mph}$
D) $90 \mathrm{mph}$

Question

Quizplus · Accepted Answer

The speed of the boat in still water can be found by setting up the equation $\frac{480}{x+8} = \frac{420}{x-8}$, where $x$ is the speed of the boat in still water. Solving this equation gives $x = 120 \mathrm{mph}$.

Solve the Problem 112mph112 \mathrm{mph}112mph B) 128mph128 \mathrm{mph}128mph C) 120mph120 \mathrm{mph}120mph D) 90mph90 \mathrm{mph}90mph

Solve the Problem $112 \mathrm{mph}$ B) $128 \mathrm{mph}$ C) $120 \mathrm{mph}$ D) $90 \mathrm{mph}$