Question

A steamer goes downstream from one port to another in 9 hours. It coverst the same distance upstream in 10 hrs. If the speed of the stream be 1 km/ h, find the speed of the streamer in still water and the distance between the ports.

Answer 1

Speed of steamer in still water will be 19 km per hour

Answer 2

Let D be the distance between the ports (in kilometers), and
let u be the streamer speed in still water.

Then you have these two equations


D%2F9 = u + 1, (1) ( speed equation for moving downstream )

D%2F10 = u - 1, (2) ( speed equation for moving upstream )

Distract equation (2) from (1) (both sides). You will get

D%2F9+-+D%2F10 = 2 ---> %2810D%29%2F90+-+%289D%29%2F90 = 2 ---> D%2F90 = 2 ---> D = 2*90 = 180.

Thus we found the distance. It is 180 kilometers.

Now from (1),

180%2F9 = u + 1 ---> 20 = u + 1 ---> u = 20-1 = 19.

The treamer speed in still water is 19 km%2Fh.