August 2007
Intermediate to advanced
190 pages
7h 38m
English
MAKE’s favorite puzzles. (When you’re ready to check your answers, visit makezine.com/11/aha.)

One hundred very smart garden gnomes are snatched from their homes by an evil wizard. He tells them he is going to line them all up in a row, and place a red or blue hat on each of their heads. They won’t be able to see the color of their own hats or anyone’s behind them, but they will be able to see the hats of the gnomes in front of them. The wizard will start at the back of the line and ask each gnome to guess the color of his own hat. Each gnome can only answer either “red” or “blue.” If ...