Question

A person covers 18 km along the stream in 4 h
and covers the same distance against the stream
in 12 h. Find the speed of stream in km/h
एक व्यक्ति धारा के अनुकूल 4 घंटे में 18 कि.मी की दूरी तय
करता है और धारा के प्रतिकूल समान दूरी 12 घंटे में तय करता
है। कि.मी. प्रति घंटा में धारा की गति ज्ञात कीजिये
A
B. 1.5
C1.75​

Answer 1

answer ⤵️

Let the speed of the boat in still water =x km/hr and the speed of the stream y km/hr.

Then, speed downstream =x+y= 18/4

= 9/2 ...(i)

and speed upstream

=x−y= 18/12= 3/2 ...(ii)

Subtracting eq (ii) from eq (i), we get,

2y= 26 =3

⇒ y=1.5 km/hr