Question 863014
D=RT
640=(R-W)*2
(R-W)=640/2=320 MPH AGAINST THE WIND.
640=(R+W)*1.33
(R+W)=640/1.33
(R+W)=481.20 MPH WITH THE WIND.
(481.20-320)/2=161.20/2=80.6 MPH IS THE WIND SPEED.
320+80.6=400.6  AVERAGE SPEED OF THE PLANE WITH NO WIND.
481.2-80.6=400.6 DITTO.