A man rows 750 m in 675 seconds against the stream and return in 15 2 minutes Find his rowing speed ......

A man rows 750 m in 675 seconds against the stream and return in 15/2 minutes. Find his rowing speed in still water.

Speed of the Upstream, U= 750/675 = 10/9 m/s
Time of downstream = 15/2 minutes = 450 seconds
(Thus, boat will return in the downstream)
Speed of downstream, D = 750/450 m/s = 5/3 m/s.
Thus, Speed of man in still water = (D + U)/2
= (5/3 + 10/9)/2 = (15 + 10) /(2 × 9) = 25/18 m/s
= 25/18 × 18/5 = 5 km/hr.

By: Manpreet kaur