A motorboat completes a round trip of 150 km between two places A and B in 8 hours. If downstream speed of the motorboat is 25 km/hr, then the upstream speed of the motorboat is
Answer & explanation
Correct answer: option 3
The correct answer is Option (3) → 15 km/hr
A round trip of 150 km means 75 km each way.
\( \displaystyle \text{Time downstream}=\frac{75}{25}=3\ \text{hours} \)
\( \displaystyle \text{Time upstream}=8-3=5\ \text{hours} \)
\( \displaystyle \text{Upstream speed}=\frac{75}{5}=15\ \text{km/hr} \)