A. 3 km/h
B. 4 km/h
C. 1 km/h ✔️
D. 2 km/h
🧠 Explanation:
A man rows 48 km and back in 14 hours, with 4 km downstream equaling 3 km upstream in time. The stream’s rate is 1 km/h. Solve: let man’s speed be x, stream’s y. Then, 4/(x+y) = 3/(x-y), and total time gives y = 1. This teaches algebra for motion problems.