A patrol boat moves at 23 km/hr when it goes downstream and at 13 km/hr when it goes upstream. What is the speed of the current?
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → 5 km/hr
The current is added to the boat’s speed one way and taken away the other way, so the downstream speed is more than the upstream speed by twice the speed of the current.
Boat \(+\) current \(=23\) and boat \(-\) current \(=13\)
Subtracting: \(2\times\) current \(=23-13=10\)
Speed of the current \(\displaystyle =\frac{10}{2}=5\) km/hr