Question

an airplane flies 240 miles against the wind in the same amount of time it takes to fly 360 miles with the wind. the speed of plane is still air is 30 mph more than 4 times the speed of the wind. Find the speed of the plane inn still air

Answer 1

let
x = speed of plane in still air
y= wind speed

x = 4*y + 30

the distance equations give us
240 = ( x - y ) *t
360 = (x +y)*t

t is the same in both equations
240 / ( x - y) = 360 / ( x + y )

now plug in x = 4y + 30 for x