The speed of wind and speed of plane in still air are 23 and 135 km/h respectively.
<u>Step-by-step explanation:</u>
Let the speed of wind and speed of plane in still air are w and p km/h respectively.
The effective speed on onward journey was
................(1)
The effective speed on return journey was
..............(2)
Adding equation (1) and equation (2) we get,
⇒
⇒
⇒
Putting value of in
we get:
⇒
⇒
⇒
Therefore ,The speed of wind and speed of plane in still air are 23 and 135 km/h respectively.