A man walks to a viewpoint and returns to the starting point by his car maintaining constant speed and thus takes a total time of 6 hours 15 minutes. He would have gained 2 hours by driving both ways. How long would it have taken for him to walk both ways with same walking speed?

Correct option is C

Given:
A man walks to a viewpoint and returns by car, taking a total time of 6 hours 15 minutes.
If he drives both ways, he would have saved 2 hours.
Find the time it would take for him to walk both ways.
Solution:
Let:
​$$t_w$$​= time taken to walk one way.
​$$t_c$$​ = time taken to drive one way.
From the given information:
​$$t_w + t_c = 6.25 \, \text{hours} \quad \text{(1)}$$​​
​$$2t_c=(6.25−2) = 4.25 \, \text{hours} \quad \text{(2)}$$​​
From equation (2):
​$$t_c = 2.125 \, \text{hours}.$$​​
Substitute $$t_c = 2.125$$​ into equation (1):
​$$t_w = 6.25 - 2.125 = 4.125 \, \text{hours}.$$​
 Time to walk both ways:
​$$2t_w = 2 \times 4.125 = 8.25 \, \text{hours} = 8 \, \text{hours} \, 15 \, \text{minutes}.$$​