A boat can go 360 m still water in 2 min, if the speed of the stream is 2 m/sec. How much time it shall take to cover the same distance in downstream?
Answer & explanation
Correct answer: option 4
Time = 2 min = 120sec.
Speed of boat in still water = \(\frac{distance}{time}\) = \(\frac{360}{120}\) = 3m/sec
Speed of boat in downstream (D.S.) = speed of boat in still water + speed of stream
D.S. = 3 + 2 = 5m/sec
Time to cover the same distance in D.S. = \(\frac{360}{5}\) = 72 sec