Mattie Evans drove 80 miles in the same amount of time that it took a turbopropeller plane to travel 400 miles. The speed of the plane was 160 mph faster than the speed of the car. Find the speed of the plane.
We begin with the formula d=rt, where d is distance, r is rate (speed) and t is time. The time is the same for both vehicles, so we will solve the formula for t:
d=rt
Divide both sides by r: d/r = t
We know that the time is the same for both vehicles so this sets up a proportion: d/r = d/r
The car travels 80 miles at an unknown speed, x: 80/x = d/r
The plane travels 400 miles at 160 mph faster than the unknown speed: 80/x = 400/(x+160)
