Question

Question 8 (1 point)

Flying with the wind a plane went 189 km/h. Flying into the same wind the plane only went 155

km/h. Find the speed of the wind and the speed of the plane in still air. (write and solve a system

of equations)

Answer 1

The Speed of the plane in still air and wind are 172 and 17 km per hour respectively

Explanation:

Let the speed of the plane in still air and speed of wind are

P and W km per hour.

The speed of the plane with wind is

P+W=189 km per hour ______________ (1)

The speed of the plane against wind is

P-W=155 km per hour __________________ (2)

Now Adding equations (1) and (2) we get

P+W=189

`P-W=155`

______________

`2P=344`

`P=(344)/(2)`

∴ P=172

Substituting the values of P in the equation (1) we get

`172+W=189`

`W=189-172`

`W=17`

∴ W=17

∴ the values of P and W are 172 ad 17 respectively

Hence the Speed of the plane in still air and wind are 172 and 17 km per hour respectively.