Problem of the Week 1003

Profit and Loss

The board of directors of the Problems For Fun corporation meets every n months. At the most recent meeting, the CEO observed that, over the period since the last meeting, the company made a profit in each 8-month interval. The CFO then said: "Yes, but in each 5-month interval over that period we lost money." What is the largest possible value of n?

Source: A wonderful new problem book by Peter Winkler: "Mathematical Puzzles, The Connoisseur's Collection" by AK Peters. That collection contains several puzzles that will be familiar to PoW enthusiasts, and many new ones, with an emphasis on algorithms that will appeal to computer scientists and tricky probability problems.

© Copyright 2004 Stan Wagon. Reproduced with permission.