Question

A pilot can fly 2100 miles with the wind in the same time she can fly 1890 miles against the wind. If the speed of the wind is 25 mph, find the speed of the plane in still air

Answer 1

475 mph

Explanation:

Distance = rate × time

time = distance / rate

If x is the speed of the plane in still air:

2100 / (x + 25) = 1890 / (x − 25)

Cross multiply:

2100 (x − 25) = 1890 (x + 25)

Distribute and solve:

2100x − 52500 = 1890x + 47250

210x = 99750

x = 475