arithmetic - a man can row 10 kmph in still water and the river is running at 2 kmph if the man takes 1 hr to row to a place and back how far is the place - skillgun

Man’s rate downstream = (10 + 2) kmph = 12 kmph
Man’s rate upstream = (10 – 2) kmph = 8 kmph
Let the reqd. distance be x km
Then x/12 + x/8 = 1
=> 20x = 96
=> x = 4.8
Hence, the required distance is 4.8 km.