Question

A man rows to a place 48 km distant and comes 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. \(3\) km/hr
• E. \(1.75\) km/hr

Answer 1

The Correct Option is A

Concept:

• Downstream = \(b + s\)
• Upstream = \(b - s\)

Step 1: Given condition.
\[ \frac{4}{b+s} = \frac{3}{b-s} \]
Step 2: Solve ratio.
\[ 4(b-s) = 3(b+s) \] \[ 4b - 4s = 3b + 3s \Rightarrow b = 7s \quad \cdots (1) \]
Step 3: Total time.
\[ \frac{48}{b+s} + \frac{48}{b-s} = 14 \] Substitute \(b = 7s\): \[ \frac{48}{8s} + \frac{48}{6s} = 14 \] \[ \frac{6}{s} + \frac{8}{s} = 14 \Rightarrow \frac{14}{s} = 14 \Rightarrow s = 1 \]
Step 4: Option analysis.

• (A) Correct \checkmark
• Others incorrect $\times$

Conclusion:
Thus, the correct answer is
Option (A).