Ram cycles from a place A to B and again back to A at a uniform speed of 12 km/h. His friend Gopi sails on a boat from A to B and back to A where his still water speed is 10 km/h and flow of river is 4 km/h. Who will return to A first?

Correct option is B

Given:

Speed of Ram = 12 km/h

Speed of Gopi in still water = 10 km/h

Speed of flow = 4 km/h

formula used:

Speed = Distance/Time

Average speed =2xy/(x+y)

Solution:

Uniform speed of Ram = 12 km/h

Upstream of Gopi = 10 – 4 = 6 km/h

Downstream of Gopi = 10 + 4 = 14 km/s

Average speed of Gopi =$$\frac{(2×6×14)}{(6+14)}$$​ 

= $$\frac{(2×6×14)}{20}$$​

= 84/10

= 8.4 km/h

Thus, Ram return to A first.