Question

A helicopter flies 200 miles against the wind in 2 hours, with the wind, it can fly 300 miles in the same amount of time. Find the speed of the helicopter in still air.

Answer 1

Against the wind, the helicopter's speed is (200 mi)/(2 h) = 100 mi/h.
With the wind, the helicopter's speed is (300 mi)/(2 h) = 150 mi/h.

The speed in still air is the average of these, (100 +150)/2 mi/h = 125 mi/h.