You have a terminal disease, for which you must take two pills a day -- one "A" pill and one "X" pill.

The pills are solid, white, and indistinguishable from eachother in every regard.

If you fail to take either pill on a given day, you die. If you take two of either the A pill or the X pill on a given day, you die.

One morning, you tap one A pill into your hand, and then accidentally knock two X pills into your hand. You now have three pills, but you don't know which are the X pills and which one is the A pill! The pills cost $10,000 each, so you dare not waste one.

How can you ensure you take only 1 A pill and 1 X pill today, without wasting any pills either now or in the future?

(Note that the pill bottles contain different numbers of pills to begin with, so you don't know which pill you took two of.)

Copyright © 2009 Elaine Simmt