Question

A swimmer's speed in the direction of flow of river is $16km{h}^{-1}$ . Against the direction of flow of river, the swimmer's speed is $8km{h}^{-1}$ Calculate the swimmer's speed in still water and the velocity of flow of the river.

• A. $12km/h,4km/h$
• B. $10km/h,3km/h$
• C. $10km/h,4km/h$
• D. $12km/h,3km/h$

Answer 1

The correct option is A $12km/h,4km/h$

Let$x$ be the speed of the still water and $c$ be the speed of the river.

Then

$x+c=16$

$x-c=8$

By solving these two equations we get

Swimmers speed in still water is $=12\frac{km}{hr}$

Velocity of flow of river$=4\frac{km}{hr}$