Answer:
55 mph
Step-by-step explanation:
Assuming that
v = velocity of the plane in still air,
w = velocity of the wind.
We are given that v = 360 mi/hr.
Using the equation
x = vt
where
x is the distance an object travels
v is the speed of the object
t is the time taken
While the plane is flying downwind, the velocity becomes v + w. On the other hand, if it is flying upwind, the velocity becomes v - w.
For a particular time t = T, distance traveled x = 210 mi at downwind, and x = 150 mi at upwind.
Creating an equation from the two, we have
210 mi = (360 + w)T
150 mi = (360 - w)T
Solving for T, we have
T = 210/(360 + w)
T = 150/(360 - w)
And since T is the same in both cases, we say that
So, 210/(360 + w) = 150/(360 - w)
Or on rearranging,
(360 + w)/210 = (360 - w)/150
(360)(150) + 150w = (210)(360) - 210w
55800 + 150w = 75600 - 210w
360w = 19800
Therefore, the speed of the wind is 55 mile per hour
