Question

A streamer goes downstream from 1 port to another in 9 hrs. It covers the same distance upstream in 10hrs.if the speed of thr stream be 1km/hfind the speed of the streamer in still water nd distance between the ports

Answer 1

The distance between the ports is 10km.

Answer 2

Lets write all the information we can get from this question:

Let the speed of streamer in still water = x km/hr
The speed of stream is = 1 km/hr

The speed of streamer in downstream = (x+1) km/hr (as the streamer is going towards the direction of water current)

The speed of streamer in upstream = (x-1) km/hr (as the streamer is going against the direction of water current)

Time taken to cover downstream = 9 hrs
Time taken to cover upstream = 10 hrs

Distance traveled by streamer in downstream = [(x+1) * 9] km (as distance = speed * time)

=9x+9 km

Distance traveled by streamer in upstream = [(x-1) * 10] = 10x-10

Now as both covers equal distances we can relate the equation as follows: 

9x+9 = 10x-10
10x-9x = 10+9
x= 19

As we know we took the speed of streamer as x therefore the speed of the streamer in still water is 19 km/hr.

The distance between the ports can be found by putting the value of x
 (10*19) - 10 = 190-10 = 180 km