Ravi rows at 10 km/hr in still water, and the river flows at 2 km/hr. He rows from his village to a market downstream and back. The return journey takes 1 hour more than the outward journey. How far is the market from the village?
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → 24 km
The market is downstream, so the outward journey is with the river and the return is against it. The return time minus the outward time is 1 hour.
Let the distance be \(d\) km
Downstream speed \(=10+2=12\) km/hr, upstream speed \(=10-2=8\) km/hr
\(\displaystyle \frac{d}{8}-\frac{d}{12}=1\)
\(\displaystyle \frac{3d-2d}{24}=1\), so \(d=24\) km
Check: \(24\div8=3\) hr back and \(24\div12=2\) hr out; the difference is 1 hr