A man rows upstream a distance of 28 km in 4 hr and rows downstream a distance of 50 km in 2 hr. To row a distance of 28.8 km in still water, he will take?

1.8 hr

ATQ,

       (U.S) Upstream speed = \(\frac{28}{4}\) = 7 km/hr.

       (D.S) Downstream speed = \(\frac{50}{2}\) = 25 km/hr.

Speed of the Man in still water = \(\frac{D.S + U.S}{2}\) = \(\frac{25 + 7}{2}\) = 16

      Time taken to cover a distance of 28.8 km = \(\frac{28.8}{16}\) = 1.8 hr.