The speed of a boat in still water is 17 km/hr and the speed of a stream is 11 km/hr. Find the difference between the upstream and downstream speed of the boat.

22km/hr

Speed of upstream = Speed of boat in still water - Speed of stream

                            = 17 - 11 = 8 km/hr

Speed of downstream = Speed of boat in still water + Speed of stream

                                = 17 + 11 = 28 km/hr

Difference = 28 - 8 = 20 km/hr