Are you ready for a brain twister? Murphy can row at 5 kmph in still water. If the velocity of current is 1 kmph and it takes him 1 hour to row to a place and come back, how far is the place?

Distance covered = speed x time

The distance traveled going against the stream = distance traveled with the stream.

Therefore it is the speed and the time that are the variables.

As he travels the same distance both ways, speed x time is the same for each way.

Going upstream his speed is 4 kph; going downstream his speed is 6 kph.

Therefore we have two simultaneous equations:

Time upstream x 4 = Time downstream x 6

Time upstream + time downstream = 60 minutes

Therefore we have the equation:

Time upstream = 6/10 hour, time downstream therefore = 4/10 hour.

Distance traveled at 4km/hr in 6/10 hour = 24/10 = 2.4km.

Check: Distance traveled at 6km/hr in 4/10 hour = 24/10 = 2.4km.