It took a crew 3 h 20 min to row 5 km upstream and back again. if the rate of flow of the stream was 2 km/h, what was the rowing speed of the crew in still water?

Suppose rowing speed is V km/s.

So, upstream speed = V-2

Downstream speed = V+ 2

Total time is taken 3 h 20 min to cover up and down journey of 5 km.

So, total time =   upstream time  + downstream time

and , we take only positive velocity.

Thus, the the rowing speed of the crew in still water is 1 km/s.