A man rows to a place 48 km distant and come back in 14 hours. He finds that he can row 4 km with the stream in the same time as 3 km against the stream. The rate of the stream is:

Answer: Option A

Suppose he move 4 km downstream in x hours
Then,
Speed downstream = $$\frac{4}{x}$$ km/hr
Speed upstream = $$\frac{3}{x}$$ km/hr
$$\begin{array}{rl}& \therefore \frac{48}{\left(4/x\right)}+\frac{48}{\left(3/x\right)}=14orx=\frac{1}{2}\end{array}$$
So, Speed downstream = 8 km/hr
Speed upstream = 6 km/hr
∴ Rate of the stream
= $$\frac{1}{2}$$(8 - 6) km/hr
= 1 km/hr