Question

at maximum speed, an airplane travels 1720 miles against the wind in 5 hours. Flying with the wind, the plane can travel the same distance in 4 hours. let x be the maximum speed of the plane and y be the spped of the wind. what is the speed of the plane with no wind?

Answer 1

If "an airplane travels 1720 miles against the wind in 5 hours", then

1720 = (x - y)*5

and if "Flying with the wind, the plane can travel the same distance in 4 hours", then

1720 = (x+y)*4


So we have a system of 2 equations with 2 unknowns. Solve this system to find your answer.