A boat running downstreams covers a distance of 30 kms in 2 hours. While coming back the boat takes 6 hours to cover the same distance. If the speed  of the current is half that of the boat, what is the speed of that boat in kmph?

A man can row at a speed of $$4{1\over 2}$$km/hr in still water. If he takes 2 times as long to row a distance upstream as to row the same distance downstream, then the speed of stream (in km/hr) is : 

A boat covers 24 km upstream and 36 km downstream in 6 hours, while it covers 36 km upstream and 24 km downstream in $$6{1\over 2}$$ hours. The speed of the current is: 

A motorboat covers a certain distance downstream in a river in 3 hours. It covers the same distance upstream in 3 and half an hour. If the speed of the water is 1.5 km / h, then the speed of the boat in still water is: 

A boat rows downstream covers a distance of 20 km in 2 hrs while it covers the same distance upstream in 5 hrs. Then speed of the boat in still water is : 

A man swims downstream distance of 15 km in 1 hour. If the speed of the current is 5 km/ hr, the time taken by the man to swim the same distance upstream is : 

The speed of the motorboat in still water is 45 kmph. If the motorboat travels 80 km along the stream in 1 hour 20 minutes, then the time taken by it to cover the same distance against the stream will be: 

The speed of a boat downstream is 15 km/hr. and the speed of current is 3 km/hr. Find the total time taken by the boat to cover 15 km upstream and 15 km downstream.