Question

A man can row three-quarters of a kilometre against the stream in 11 1/4 minutes and down the stream in 7 1/2 minutes. The speed (in km/hr) of the man in still water is

Answer 1

Answer:

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speed upstream = 3/4 * 2/15 * 60 km/hr = 4 km/hr

Speed downstream = 3/4 * 2/15 * 60 km/hr = 6 km/hr

Therefore  

Speed in still water = 1/2 (4+6) km/hr = 5 km/hr