What is downstream speed when speed of boat in still water and speed of stream are given

What is upstream speed when speed of boat in still water and speed of stream are given

A boat takes 10 hours to travel 30 km upstream and 44 km downstream, but it takes 13 hours to travel 40 km upstream and 55 km downstream. Find the speed of the boat in still water and the speed of the stream.

A boat goes 30 km downstream and while returning covered only 80% of distance that covered in downstream . If boat takes 4 hr more to cover upstream than downstream then find the speed of boat in still water (km/hr) if speed of stream is (25)/(36) m/sec ?

A boat covers 20 km in an hour with downstream and covers the same distance in 2 h with upstream. Then, find the speed of boat in still water and speed of stream.

Downstream speed of boat is 50 km/h and upstream speed of boat is 30 km/h. Find the speed of boat in still water and speed of stream?

Speed of boat in still water when speed of downstream and upstream are given.

The speed of a boat in upstream is 2/3 that of downstream. Find the ratio of speed of boat in still water and to the average speed of boat in downstream and upstream?