The Covetous Neighbors
RAY: Here’s how you solve it. If you draw this grid, the square in the upper left-hand corner we could say is one, and the one next to it is two, three, four, five, and then the line below that is six, seven, eight, nine, 10, 11, 12, right? All the way to 25.
Let's letter the first one A. The next one B, the next one A, the next one B, et cetera, et cetera. Then, everyone who's on an A square must, by definition, move to a B square. And everyone who's on a B square must move to an A square.
Now, if you add them up, you got 13 A squares and only 12 B squares. So, there are no fewest number of moves. It’s impossible for this to happen.
Do we have a winner?
TOM: The winner is Martha Lozzanno from Richmond, Virginia. Congratulations, Martha!
[ Car Talk Puzzler ]