A duck can fly 2400 m in 10 minutes with the wind Against th

A duck can fly 2400 m in 10 minutes with the wind. Against the wind, it can fly only 2/3 of this distance in 10 minutes. What is the rate of the wind?

2,400/10=240 m/m.
2/3*2,400/10=2*800/10=1,600/10=160 m/m.
(240-160)/2=80/2=40 m/m is the speed of the wind.
Proof:
240-40=200 m/m. is the speed of the duck.
160+40=200 ditto.