Question

A boat travels 10km upstream and 5km
downstream in 3hrs. If the speed of the
boat in still water is 7kmph. Find the
speed of the stream.
Select one:
a. 1kmph
b. 1.5kmph
c. 2kmph
d. 3kmph​

Answer 1

Answer:

x=3kmph

Explanation:

let speed of boat in still water is y=7kmph

and the speed of running water be=xkmph

Let the speed of the stream be x kmph.

Upstream speed = (7-x) kmph

Downstream speed = (7+x) kmph .

Time taken to travel upstream = (10/(7-x)) hrs

Time taken to travel upstream = (5/(7+x)) hrs

Speed of the stream =>(10/(7-x)) + (5/(7+x)) = 3

3x2+5x-42=0

Solving this equation, x=3