Neha can swim at 3 km/hr in still water. The river flows at 1.5 km/hr. How far will she swim down the river in 40 minutes?
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → 3 km
Down the river the current helps Neha, so its speed is added to her swimming speed; the minutes are changed to hours first.
Downstream speed \(=3+1.5=4.5\) km/hr
Time \(\displaystyle =40\text{ min}=\frac{40}{60}=\frac{2}{3}\) hr
Distance \(\displaystyle =4.5\times\frac{2}{3}=3\) km