Answer:
The rate of wind is 20 mph.
Step-by-step explanation:
The actual speed of the plane is 100 mph.
Now, it is given that, the plane takes the same time to travel 360 miles with the flow of air and to travel 240 miles against the flow of air.
Let the equal time is t hrs.
If, the speed of the plane is u and that of wind is v then we can write,
360/t =u+v ....(1) and
240/t =u-v .....(2)
Now, adding (1) and (2), we get, 2u =600/t, ⇒ 2×100 =600/t, ⇒t = 3 hours.
Hence, from equation (2), we get v = u-240/t, ⇒ v =100-240/3 =20 mph
Therefore, the rate of wind is 20 mph. (Answer)