Against wind :2400 miles in 10 hours
With wind : 2400 miles in 8 hours
Speed of plane = x
Speed of wind = y
t=d/r
against the wind speed x-y mph
with the wind x=y mph
2400/(x-y)=10
2400 = 10x-10y
240 =x-y eq.1
2400/x+y=8
2400 = 8x+8y
300 = x+y eq 2
Add eq1 & eq 2 = 740 = 2x
X = 740/2 = 370 mph for plane
300 = 370 +y
Y = 370-300 = 70 mph wind speed