Expanding Minds / Increasing Performance

This week we are posting  5 "Insight Problems" one for each day of the work week.

Tues February 22, 2011, Second Day

Todays problem is:

Two men played five full games of checkers and each won an even number of games, with no ties, draws, or forfeits. How is that possible?

(Baker-Sennett & Ceci, 1996; Jacobs & Dominowski, 1981; Schooler & Melcher, 1995).