How to Solve Watershare XLS

The goal is one empty jug and two equal portions to share.

The Watershare Puzzle is a mathematical brain teaser that started in Microsoft Excel and went viral on the Internet. In the puzzle, you have three different-sized jars, two containing water, and you need to pour the water back and forth between the jars until you end up with an equal amount in two jars and nothing in the third jar. You start with an empty 19-liter jar, a full 13-liter jar and a full 7-liter jar. At the end of the puzzle, you should have one empty jar and two jars containing 10 liters of water each.

Instructions

1. Pour the contents of the 7-liter jar into the 19-liter jar.

   Start: 0 - 13 - 7
   End: 7 - 13 - 0

2. Pour the contents of the 13-liter jar into the 19-liter jar.

   Start: 7 - 13 - 0
   End: 19 - 1 - 0

3. Fill the 7-liter jar with water from the 19-liter jar.

   Start: 19 - 1 - 0
   End: 12 - 1 - 7

4. Pour the contents of the 7-liter jar into the 13-liter jar.

   Start: 12 - 1 - 7
   End: 12 - 8 - 0

5. Fill the 7-liter jar with water from the 19-liter jar.

   Start: 12 - 8 - 0
   End: 5 - 8 - 7

6. Fill the 13-liter jar with water from the 7-liter jar.

   Start: 5 - 8 - 7
   End: 5 - 13 - 2

7. Pour the contents of the 13-liter jar into the 19-liter jar.

   Start: 5 - 13 - 2
   End: 18 - 0 - 2

8. Pour the contents of the 7-liter jar into the 13-liter jar.

   Start: 18 - 0 - 2
   End: 18 - 2 - 0

9. Fill the 7-liter jar with water from the 19-liter jar.

   Start: 18 - 2 - 0
   End: 11 - 2 - 7

10. Pour the contents of the 7-liter jar into the 13-liter jar.

    Start: 11 - 2 - 7
    End: 11 - 9 - 0

11. Fill the 7-liter jar with water from the 19-liter jar.

    Start: 11 - 9 - 0
    End: 4 - 9 - 7

12. Pour the contents of the 7-liter jar into the 13-liter jar.

    Start: 4 - 9 - 7
    End: 4 - 13 - 3

13. Pour the contents of the 13-liter jar into the 19-liter jar.

    Start: 4 - 13 - 3
    End: 17 - 0 - 3

14. Pour the contents of the 7-liter jar into the 13-liter jar.

    Start: 17 - 0 - 3
    End: 17 - 3 - 0

15. Fill the 7-liter jar with water from the 19-liter jar.

    Start: 17 - 3 - 0
    End: 10 - 3 - 7

16. Pour the contents of the 7-liter jar into the 13-liter jar.

    Start: 10 - 3 - 7
    End: 10 - 10 - 0

Tips & Warnings

• If you make a mistake, you can always pour all the contents back into 19-liter jar and the last liter into the 13-liter jar to start over.

References

• e-Nager: Watershare

Resources

• Scribd: Watershare Puzzle