Including stoppages the speed of a bus is 60 km/hr and excluding stoppages its speed is 65 km/hr. For how long the bus stops in an hour?

4 min

Without stoppage speed = 65 Km/hr

It means, the bus goes:

65 km in = 60 min

01 km in = \(\frac{60}{65}\) min

05 km in = \(\frac{60}{65}\) × 05 min = 4.6 min (approx) ....(i)

Now,

With stoppage, speed of bus = 60 Km/hr

The bus goes 60 km in = 60 min.

It means, the bus cannot travels 5 km due to stoppage and it can go 05 km in 4.6 min as eq.-(i)

Therefore, the bus stops for 4.6 min or 4 min (as per option) in one hour.