Boats and Streams::: > Speed of a swimmer when moving in the direction perpendicular to the direction of the current is 16km/h,speed of the current is 3km/h,so the speed of the swimmer against the current will be In this Question swimmer moving in the direction perpendicular to the direction,it denotes upstream or Downstream If downstream means relative speed will be we can add the swimmer speed and current speed and upstream means relative speed will be we can subtract the swimmer speed and current speed **`But in this question I cannot proceed further , can anyone explain and solve the answer please`** **Perpendicular direction means denotes which direction ?**

It's easy -

Speed in perpendicular directionhere means downstream speed.

If swimmer is moving at speed of 16 kmph in downstream. It means his speed is increased by current. And increase in speed is equal to current speed. So if you subtract current speed from downstream speed. You get swimmer speed in still water. So we have 16-3=13 kmph as speed of swimmer.

As current speed is 3 kmph. Suppose you pick swimmer from still water and drop against current to swim. As we know it's hard to swim against current. So speed decrease. And decrease in speed is equal to current speed.

We have 13-3=10 kmph.