A man rows 15 km upstream in 5 hours and 25 km downstream in 5 hours. The speed of the current is:
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → 1 km/h
\( \displaystyle \text{Upstream speed}=\frac{15}{5}=3\ \text{km/h} \)
\( \displaystyle \text{Downstream speed}=\frac{25}{5}=5\ \text{km/h} \)
The current slows the boat upstream and speeds it up downstream by the same amount, so the speed of the current is half the difference:
\( \displaystyle \text{Speed of current}=\frac{5-3}{2} \)
\( =1\ \text{km/h} \)
CBSE Applied Mathematics (Class XII):
Boats and Streams
