A fishing boat moves at 18 km/hr in still water. The river flows at 3 km/hr. How long will the boat take to travel 45 km upstream?
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → 3 hours
Going upstream, the river works against the boat, so the river’s speed is taken away from the boat’s speed.
Upstream speed \(=18-3=15\) km/hr
Time \(\displaystyle =\frac{45}{15}=3\) hours