Two men start travelling from the same place in the same direction at the rate of 5 km/h and 5.5 km/h respectively. To be 8.5 km apart from each other, the time taken by them is:

Correct option is B

Given:

Speed of the first man = 5km/h
Speed of the second man = 5.5 km/h
Distance apart = 8.5 km

Formula Used:

The relative speed when two objects move in the same direction is the difference in their speeds: Relative speed = 5.5 - 5 = 0.5 km/h

Solution:

Time taken to be 8.5 km apart is given by the formula:
Time = $$\frac{\text{Distance}}{\text{Relative speed}}$$​​

Substituting the values into the formula:
Time = $$\frac{8.5}{0.5}$$​​

= 17 hours

Thus, the time taken by them to be 8.5 km apart is 17 hours.