Question

Flying against the wind, an airplane travels 3920 kilometers in 4 hours. Flying with the wind, the same plane travels 12,780 kilometers in 9 hours. What is the rate of the plane in still air and what is the rate of wind ?

Answer 1

Velocity against wind= V - v = 3920/4

Velocity with wind= V + v = 12780/9

Its a 2x 2 system to need be solved

Adding both equations results in

2V = 3920/4 + 12780/9

V = 3920/8 + 12780/18 = 490 + 710 = 1200 km/hour

Now find v

v= V - 3920/4= 1200- 980= 220 km/hour