a plane travels 5100 miles with the wind in 7.5 hours and 4200 miles against the wind in the same amount of time. Find the speed of the plane in still air and the speed of the wind.

Answer 1

Let x = speed of plane in still air and y = speed of wind

Speed of plane with the wind = x + y and speed of plane against the wind = x - y

Distance = (Rate)(Time)

5100 = 7.5(x + y)

4200 = 7.5(x - y)

Add the equations to get 15x = 9300

Solve for x and y.