Saturday, May 17, 2008

3 litres and 5 litres containers puzzle

Puzzle: You have two container - one can contain exactly 3 litres of water and the other can contain exactly 5 litres of water. How many minimum steps will you take to get exactly 4 litres of water without using any other container? You can assume the availability of sufficient quantity of water.


Solution: Find below the steps:-

  • Step #1: fill the 5 litres container (3L - 0, 5L - 5)
  • Step #2: fill the 3 litres container with the filled 5 litres container (3L - 3, 5L - 2)
  • Step #3: empty the just filled 3 litres container (3L -0, 5L - 2)
  • Step #4: transfer the 2 litres of water left in 5 litres container into 3 litres container (3L - 2, 5L - 0)
  • Step #5: fill the 5 litres container (3L - 2, 5L - 5)
  • Step #6: fill the 3 litres container (having 2L currently) using just filled 5 litres container (3L - 3, 5L - 4)
So in a minimum of 6 steps you get exactly 4L of water in the 5 litres container.

5 comments:

  1. this is really good

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  2. very good.. thanks alot...

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  3. or u can follow the following procedure...
    i) Assuming both the containers empty, fill the 3 litre container and pour the water in 5 litre container.
    so 3L-0, 5L-3
    ii) Again fill the 3 litre container and pour the water in 5litre container until it gets full. As 5 litre container contains already 3 litre water, it will have more 2 litre water now (in all 5) and 3 litre container will have 1 litre left in it.
    so 3L-1, 5L-5

    iii) Throw the water in 5L container and pour all the water from 3litre container to 5L container.
    So 3L-0, 5L-1.

    iv) now fill the 3 litre container full and pour the water in 5litre container which will give us 4 litres of water.

    ReplyDelete
  4. A more involved version of the problem and the solution can be found here on CSE Blog

    ReplyDelete
  5. A more involved version of the problem and the solution can be found here on CSE Blog

    ReplyDelete