A car travels between two stations with an average speed of 60 km/hr and comes back with average speed of 90 km/hr. What is the average speed of the car in the whole journey ?

Correct option is C

Given:

$$v_1$$ = 60 km/hr ​
​$$v_2$$​ = 90 km/hr

Solution:
Substitute the values into the formula:


Average Speed = $$\frac{2 \times 60 \times 90}{60 + 90}$$​​

Simplify step-by-step:

Average Speed = $$\frac{2 \times 5400}{150}$$​​

Average Speed = $$\frac{10800}{150}$$​​

Average Speed = 72 km/hr

Final Answer:
The average speed of the car for the whole journey is 72 km/hr.