Question 694357
D=RT
560=R*2
560=2R
R=560/2
R=280 K/H WITH THE WIND.

560=R*4
560=4R
R=560/4
R=140 K/H AGAINST THE WIND.

(280-140)/2=140/2=70 K/H IS THE SPEED OF THE WIND.
280-70=210 SPEED OF THE PLANE.
140+70=210 DITTO.