A man can swim with a speed of `4kmh^(-1)` in still water. He crosses a river 1km wise that flows steadly at `3kmh^(-1)`. If he makes his strokes normal to the river current, how far down the river does he go when he reaches the other bank?

Options

A. `500m`
B. `600m`
C. `750m`
D. `850m`

Answer

C

Explanation

Time to cross river, `t=("Width of river")/("Speed of man")`
`=(1km)/(4kmh^(-1))=1/4h`
Distance moved along the river in time t
`=V_(r)xxt=3km^(-1)xx1/4h=3/4km=750m`