Posts

Showing posts with the label swimming

A World Class Swimmer's Puzzle

A world-class swimmer can swim at twice the speed of the prevailing tide.

She swims out to a buoy and back again, taking four minutes to make the round-trip.

How long would it take her to make the identical swim in still water?


A World Class Swimming



Solution of A World Class Swimmer's Puzzle


What was the puzzle?

 Let C be the speed of water current then the speed of a world class swimmer will be 2C.

When she swims out to a buoy located at a distance say D and back again, the time needed is - 

D/(C+2C) + D/(2C-C) = 4 minutes

D/3C + D/C = 4

Multiplying both the sides by 3, 

D/C + 3D/C = 12

4D/C = 12

D/C = 3  


Now when she swims out to a buoy and back to shore again in still water, she needs only time -

D/2C + D/2C 


Since D/C = 3, then D/2C = 3/2

Hence, 
 
D/2C + D/2C  = 3/2 + 3/2 = 3.


That is, she needs only 3 minutes to swim out to a buoy and back to shore again in still water.

Swimming in a Still Water!
 
 

Flip The Orientation of the Group

Assume these matchsticks as fishes. Can you flip the positions of the fishes horizontally i.e. 1 at the leftmost position and 4 at the rightmost position. Condition is that you can move only 3 matchsticks.


Flip The Orientation of the Group



That's how it can be done!

Flipping The Orientation of The Group


What was the task given?


All we need to do is just move these sticks as shown below.

Flipping The Orientation of The Group




Follow me on Blogarama