Question

A race boat covers a distance of 66 km downstream in 110 minutes. it covers this distance upstream in 120 minutes. the speed of boat in still water is 34.5km/h. find the speed of the stream

Answer 1

Let the speed of the stream or the streamflow be x km/hr.

When the racing boat is going downstream its speed is (34.5+x) km/hr and while going upstream its speed is (34.5-x) km/hr.

66/(34.5+x) = 110/60, or

110(34.5+x) = 66*60, or

(34.5+x) = 66*60/110 = 36, or

x = 36–34.5 = 1.5 km/hr.

Check: 66/(34.5-x) = 66/(34.5–1.5) = 66/33 = 2 hours or 120 minutes. Correct.

The streamflow is 1.5 km/hr.

Answer 2

Answer:

1.5km /hr.

Explanation has given above...