Question

Question 101

Solve the following:

A streamer goes downstream and covers the distance between two ports in 3 hours. It covers distance in 5 hours, when it goes upstream. If the stream flows at 3 km/h, then find what is the speed of the steamer upstream?

Answer 1

Let speed of the steamer in still water be x km/h.
Speed of the stream =3km/h
Now, speed of the steamer downstream=(x+3) km/h
and speed of the steamer upstream=(x-3) km/h
According to the question,
Distance covered in 3 h by steamer downstream=Distance covered in 5 h by steamer upstream
$\therefore 3(x+3)=5(x-3)[\because distance=speed\times time]\Rightarrow 3x+9=5x-15\Rightarrow 3x-5x=-15-9\Rightarrow -2x=-24\Rightarrow x=-24\times \left(\frac{-1}{2}\right)=12km/h$
Hence, the speed of the steamer upstream is (12-3), i.e. 9km/h.