Kavya can swim at 2.5 km/hr in still water. The river flows at 1 km/hr. How long will she take to swim 1.75 km up the river?
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → 1 hour 10 minutes
Swimming up the river, Kavya swims against the current, so the river’s speed is taken away from her own speed.
Speed up the river \(=2.5-1=1.5\) km/hr
Time \(\displaystyle =\frac{1.75}{1.5}=\frac{7}{6}\) hours
\(\displaystyle \frac{7}{6}\) hours \(\displaystyle =1\) hour \(+\,\frac{1}{6}\times60\) minutes \(=1\) hour 10 minutes