A boat is moving 3 km against the current of the stream in 1 hour and moves 1 km in the direction of the current in 12 minutes. How long will it take the boat to go 6 km in stationary water?
Show answer & explanation
Correct answer: C
Explanation
The correct answer is option 3 i.e. 1 hour and 30 minutes.
Let the speed of the boat and stream be x and y respectively.
Given that:
The boat is moving 3 km against the current of the stream in 1 hour and it moves 1 km in the direction of the current in 12 minutes.
So, according to the question:
Upstream speed = x - y = 3 .......(1
Downstream speed = x + y = 60/12 = 5
⇒ x + y = 5 ......(2
Now,
Equation 1 + Eqaution 2
⇒ 2x = 8
⇒ x = 4 km/h
Hence,
Time taken by boat to travel 6 km in still water = 6/4 hour = 1 hour and 30 minutes