A jet plane traveling at a constant speed goes 1300 miles with the wind, then turns around and travels for 1100 miles against the wind. If the speed of the wind is $50 \mathrm{mph}$ and the total flight took 4 hours, find the speed of the plane in still air.
A) $575 \mathrm{mph}$
B) $600 \mathrm{mph}$
C) $485 \mathrm{mph}$
D) $655 \mathrm{mph}$

Question

Quizplus · Accepted Answer

Let the speed of the plane in still air be $x$ mph. With the wind, the plane's speed is $x + 50$ mph, and against the wind, it's $x - 50$ mph. The total time taken is the sum of the time with the wind and the time against the wind, which equals 4 hours. So, we have the equation: $\frac{1300}{x + 50} + \frac{1100}{x - 50} = 4$. Solving this equation for $x$ gives $x = 600$ mph.

A Jet Plane Traveling at a Constant Speed Goes 1300 50mph50 \mathrm{mph}50mph

A Jet Plane Traveling at a Constant Speed Goes 1300 $50 \mathrm{mph}$