Question

a streamer goes downstream from one part to another in 9 hours. It covers the same distance upstream in 10 hours. If the spread of the stream is 1 km/h, find the spread of the streamer in still water and the distance between the ports.

Answer 1

Answer: Speed of streamer = 19 km/h (in still water), distance = 180 km.

Explanation:

Let, speed of streamer = x km/h

& distance between the points = y km

We know,

t = s/v,

& t1 = 9 (Downstream)

So, in downstream: y/(x + 1) = 9

=> y = 9(x + 1) ___(1)

Again, t2 = 10 h (Upstream)

=> y/(x - 1) = 10

=> y = 10(x - 1) ___(2)

From (1) & (2):-

9(x + 1) = 10(x - 1)

=> 10x - 10 = 9x + 9

=> 10x - 9x = 9 + 10

=> x = 19 km/h.

By putting the value in any of the equation, we get y = 180 km.