Ayush starts his journey from Chandigarh to Ludhiana with his car at a speed of 77 km/hr and returns at a speed of 63 km/hr. If the distance between Chandigarh and Ludhiana is 97 km, then what is the average speed (in km/hr) of Ayush during his whole journey?

Correct option is D

Given:
Ayush travels from Chandigarh to Ludhiana at 77 km/hr and returns at 63 km/hr.
Distance between Chandigarh and Ludhiana = 97 km.
Formula Used:
For a round trip with different speeds for the same distance:
​$$\text{Average Speed} = \frac{2xy}{x + y}$$​​
Where x and y are the speeds during the onward and return journeys.
Solution:
Let: $$x = 77 \text{ km/hr}, \quad y = 63 \text{ km/hr}$$​​
​$$\text{Average Speed} = \frac{2 \times 77 \times 63}{77 + 63}= \frac{9702}{140} = 69.3 \text{ km/hr}$$​​