The story got me thinking about the probability of 6 non-matching feet from 6 bodies. It's a bit like one of those programmer test logic/probability puzzles, only more morbid. How likely is it that six feet from six unique bodies would wash ashore?

Assuming there are six bodies, the sequence of probabilities for discovering unmatched feet is:

With six bodies and six unique feet, the probability is just less than 7%, which suggests that the feet more likely are from a pool of more than six bodies.

More generally, the probability works out to:

where *a* is the total number of bodies and *b* is the number of feet found so far.

If you want to play with the probabilities (perhaps as more feet are discovered), you can use the attached spreadsheet.

foot_math.xls