A ferry moves at 22 km/hr in still water. It takes 3 hours to go 54 km upstream. How long will it take to go 65 km downstream?
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → 2 hours 30 minutes
The upstream run gives the stream’s speed (the ferry loses that much against the stream); the ferry gains the same amount going downstream.
Upstream speed \(\displaystyle =\frac{54}{3}=18\) km/hr
Speed of the stream \(=22-18=4\) km/hr
Downstream speed \(=22+4=26\) km/hr
Time \(\displaystyle =\frac{65}{26}=2.5\) hours \(=2\) hours 30 minutes