Vishal covers 285 km in a boat in 45 hours against the stream and he takes 18 hours with the stream then find the speed of the stream?

Correct option is A

Given:

Distance covered by Vishal in 45hours against stream = 285km

Time taken to cover same distance in direction of stream = 18hours

Formula Used:

If u is speed of boat in still water is u and speed of stream is v then,

Speed of boat upstream/opposite to stream = (u -v)

Speed of boat downstream/in direction of stream = (u+v)

Speed $$= \frac{Distance}{Time}$$​​

Solution:

Equivalent speed of  Vishal upstream = $$\frac{285}{45} =\frac{19}{3}$$​km/hr

Equivalent speed of Vishal downstream =$$\frac{285}{18} = \frac{95}{6}$$​km/hr

Hence

u- v =$$\frac{19}{3}$$​    …(1)

u+v =$$\frac{95}{6}$$​   …(2)

Solving we get

v = $$\frac{19}{4}$$​km/hr or 4.75km/hr