The distance from A to B is 60 km. Partha and Narayan start from A at the same time and move towards B. Partha takes four hours more than Narayan to reach B. Moreover, Partha reaches the mid-point of A and B two hours before Narayan reaches B. The speed of Partha, in km per hour, is
Let the time taken by Partha to cover 60 km be x hours.
Narayan will cover 60 km in x-4 hours.
Therefore, Speed of Partha = 60/x
Speed of Narayan = 60/(x−4)
Given that, Partha reaches the mid-point of A and B two hours before Narayan reaches B. Hence,
30/(60/x) + 2 = 60/(60/(x−4))
x/2 + 2 = x − 4
x + 4 = 2x − 8
x = 12
Partha will take 12 hours to cross 60 km.
Speed of Partha = 60/12 = 5 Kmph
The correct option is C.