Answer:
third one
Step-by-step explanation:
Answer:
9 7/8 - ( -2 4/5 - 1/2) = 13.175
Step-by-step explanation:
Hope this is correct and helps.
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.