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 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 takes half time in moving a certain distance downstream than upstream. what is the ratio between the rate in still water and the rate of current? 

A boat running upstream takes 7 hours and 40 minutes to cover a certain distance while it takes 5 hours to cover the same distance downstream. What is the ratio between the speed of the current and speed of the boat respectively? 

A motorboat can travel at 10 km/hr. in still water it travelled 91 km downstream in a river and then returned taking at together 20 hours. Find the rate of flow of the river 

A man rows from J to K (upstream) and back from K to J (downstream) in a total time of 15 hours. The distance between J and K is 300 km. The time taken by the man to row 9 km downstream is identical to the time taken by him to row 3 km upstream. What is the approximate speed of the boat in still water?

A boat moves 25km upstream and 39km downstream in 8 hours. It travels 35km upstream and 52km downstream in 11 hours. What is the speed of the stream if it travels at a uniform speed?

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 -