Question

Flying against the wind, an airplane travels 4000 kilometers in 5 hours. Flying with the wind, the same plane travels 5040 kilometers in 4 hours. What is the rate of the plane in still air and what is the rate of the wind? Urgent!!

Answer 1

Answer:the plane in still air is 904 km/h

the rate of the wind is 104 km/h

Step-by-step explanation:

Let x represent the rate or speed of the plane in still air.

Let y represent the rate or speed of the wind.

Flying against the wind, an airplane travels 4000 kilometers in 5 hours. This means that the total speed of the airplane would be (x - y) km/h

Distance = speed × time

Therefore

4000 = 5(x - y)

4000 = 5x - 5y - - - - - - - - -1

Flying with the wind, the same plane travels 5040 kilometers in 4 hours. This means that the total speed of the airplane would be (x + y) km/h. Therefore,

5040 = 4(x + y)

5040 = 4x + 4y - - - - - - - - - 2

Multiplying equation 1 by 4 and equation 2 by 5, it becomes

16000 = 20x - 20y

20160 = 20x + 20y

Subtracting, it becomes

- 4160 = - 40y

y = - 4160/-40

y = 104

Substituting y = 104 into equation 1, it becomes

4000 = 5x - 5 × 104

4000 = 5x - 520

5x = 4000 + 520

5x = 4520

x = 4520/5 = 904