Question

A man rows upstream $13$ km and downstream $28$ km taking $5$ hr each time. What is the velocity in (km/hr) of the current ?

• A. $1.0$
• B. $1.2$
• C. $1.5$
• D. $1.8$

Answer 1

Answer: (C)

$1.5$

Speed upstream $=\frac{13}{5}$ km/hr $=2.6$ km/hr
Speed downstream $=\frac{28}{5}$ km/hr $=5.6$ km/hr
Therefore, $\text{Velocity of current}=\frac{1}{2}(5.6-2.6)$ km/hr $=(\frac{1}{2}\times 3)$ km/hr $=1.5$ km/hr