Question 355612
speed of plane in still air = 120mph
let speed of wind be x mph
against wind the speed will be 120-x mph
with wind the speed will be 120+x mph
..
distance trraveled forward = (120-x)*1.5  

distance traveled return = (120+x)*1
x+120 = 180-1.5x

2.5x=60
x=60/2.5
x= 24 mph the speed of wind
...
the x axis represents the wind speed
the y axis represents the cruising speed.
Green line represents against wind
red line represents with wind.
they intesect at x = 24 the wind speed
{{{graph(500,500,-10,130,-10,200,(x+120),(-1.5x+180))}}}