Question

When traveling with the wind, it takes an airplane 3 hours to travel 1800 miles. It takes the same airplane 3.6 hours to travel the same 1800 miles when traveling against the wind. Assuming the airplane travels at a constant speed during both trips, what is the speed of the airplane and the speed of the wind?

Answer 1

Answer:

The speed of the airplane in still air is 550 mph.

The speed of the wind is 50 mph.

Step-by-step explanation:

speed = distance / time

distance = speed * time

or simply

d = st

Let v be the speed of the airplane with no wind.

Let w = speed of wind

With the wind:

d = 1800; s = v + w; t = 3

1800 = 3(v + w)

Against the wind:

d = 1800; s = v - w; t = 3.6

1800 = 3.6(v - w)

We have a system of two equations:

3(v + w) = 1800

3.6(v - w) = 1800

Divide both sides of the first equation by 3. Divide both sides of the second equation by 3.6.

v + w = 600

v - w = 500

Add the equations.

2v = 1100

v = 550

The speed of the airplane in still air is 550 mph.

v + w = 600

550 + w = 600

w = 50

The speed of the wind is 50 mph.