Question

stream goes down and covers the same distance upstream in 5 hours if the speed of the stream is 2km /hour .find the speed of stream in still water ​

Answer 1

Step-by-step explanation:

Let the distance between the two ports be x km. 

Then, speed downstream = x/4 

And speed upstream = x/5 

Speed of the stream, 

= [speed downstream - speed upstream] / 2

= (x/4 - x/5)/2

Or, (5x -4x)/40 = 2

Or, x/40 = 2 

Thus, x = 80 km.

Distance between two ports = 80 km.

Answer 2

Answer:

Speed of stream = 2 km/hr

let speed of boat (in still water) = x km/hr

while going downstream  his speed = x+2 km/hr

and going upstream = x-2 km/hr

now A/Q 

dis /x+2 = 7⇒ dis = 7 (x+2)  ......(1)

and dis / x-2 = 8 ⇒ dis = 8(x-2)  ............(2)

(1) =  (2)

7x + 14= 8x - 16  ⇒ x = 30 km/hr

and dis = 7(30+2) = 7 x 32 = 224 km

hope this helps....

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