A man can swim in still water at a speed of `6 kmph` and he has to cross the river and reach just opposite point on the other bank.If the river is flowing at a speed of `3 kmph`,and the width of the river is `2km`, the time taken to cross the river is (in hours)

Options

A. `(2)/(27)`
B. `(2)/sqrt(27)`
C. `(2)/(3)`
D. `(2)/sqrt(45)`

Answer

b

Explanation

`v_(m)=6` kmph, `v_(w)=3` kmph, `t=(d)/(sqrt(v_(m)^(2)-v_(w)^(2)))`