Question

the speed of a boat downstream is 15kmph and the speed of the stream is 1.5 kmph. the speed of the boat upstream (in km/hr) is:

Answer 1

Hii..
Here is your answer..

Solution:-
In clam water, let the speed of the boat is u km/h.
And the speed of water is v km/h

Speed downstream =(u+v) km/h
◆The speed along with stream

Speed upstream =(u-v) km/h
◆The speed against the stream

Now,
We can write that,
$= > 15 = u + 1.5 \\ = > u = 13.5$
So,
We know that v =1.5
And now u =13.5

Therefore,
Speed upstream=
$= > (13.5 - 1.5) \\ = > 12km \: per \: hrs$
Hope it helps uh....☺️