Find the speed of stream from rowing speeds with and against the stream

Question

Problem

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:

(A) 1 km/hr; (B): 1.5 km/hr; (C): 2 km/hr; (D): 2.5 km/hr

Progress

I don't know how to solve these. Anybody can help me with these. Book answer is 1km/hr

Answer 1

Answer:

V = speed of the boat U = speed of the stream

$(V+U).t =4$

$(V-U)*t = 3$

$\frac{(V+U)}{(V-U)} = \frac{4}{3}$

Solving this you get $V = 7U$

$(V+U)*t_1 = 48$

$(V-U)*t_2 = 48$

$t_1 + t_2 = 14$

$8U*t_1 = 48$

$6U*t_2 = 48$

$\frac{48}{8U} + \frac{48}{6U} = 14$

Solving this we get U = 1

Thanks

Satish