Question

if a plane can travel 480 miles per hour with the wind and 380 miles per hour against the wind,find the speed of the wind and the speed of the plane in still air . what is the speed of the plane in still air .

Answer 1

Let x be the speed of the plane while still in the air and let y be the speed of the wind

so

x + y = 480mph ......(1)

x - y = 380mph ...... (2)

add both equations and solve for x

2x = 860 mph

x = 860/2=430mph = speed of the plane while stil in air

using equation .....(1)

430 + y =480 mph

y = 480 - 430 = 50 mph =speed of the wind