Friday, January 18, 2013

Draining a tank solution

See the original puzzle

You could just open all the walls, leaving only 10/9 gallons in the corner tank.  However, it's more efficient to drain it in three stages.

There are many variations on this solution, but they all leave 1/3 of a gallon.

Once you've seen this solution, finding the best solution for 16 tanks or 25 tanks is quick work--unless there's a more complicated solution that I haven't found.