The speed of a boat in still water 11 km/hr. It can go 12 km upstream and return downstream to the engine point in 2hr 45min. What is the speed of stream?

A boat covers 48 km. upstream and 72 km. downstream in 12 hours, while it covers 72 km. upstream and 48 km. downstream is 13 hours. The speed of stream is -

A man can row 10 km/h in still water. When the river is running at a speed of 4.5 km/h, then it takes him 2 h to row to a place and comes back to the initial point . How far is the place (in km) (rounded off to two decimal places)?

A boat goes from A to B in upstream and come back from B to A downstream taking a total time of 3.5 hours. If the speed of boat in still water is 7 km/hr and the speed of stream is 5 km/hr. Find the distance between A and B. 

A boat can row 15 km per hour downstream and 9 km per hour upstream. The speed (in km/hour) of the boat in still water is:

A boat goes 15 km in an hour in still water, and takes thrice the time to cover the same distance upstream. The speed of the current (in km / hr) is –

Speed of a boat in still water is 6 km/hr and speed of the current is 2 km/hr. If boat takes four hours more in upstream than in the downstream to cover ‘D’ km, then find time take by boat to cover ‘D’ km in still water?

A motorboat whose speed is 20 km/h in still water takes 30 minutes more to go 24 km upstream than to cover the same distance downstream. If the speed of the boat in still water is increased by 2 km/h, then bow much time will it take to go 39 km downstream and 30 km upstream?