# Brainteasers – Issue 5, 2005

1. Walking in Circles

A classic puzzle describes the hunter who walks a mile south, turns and walks a mile east, turns again and walks a mile north. He is surprised to find himself right back where he started. He then shoots a bear. What color is the bear? The answer is usually given as “white”, because the hunter must have started his 3 mile walk at the North Pole. Can you find some other places on the globe where you could follow those same directions and end up at your starting point?

Hint: No polar bears near any of those places!

2. Out of Sight

Fred has designed a new machine for the factory where he works. His design was followed perfectly, but he forgot to specify the order, and the labels, for four light switches on the control console. These four on-off switches are wired to four ordinary light bulbs on the far end of the machine—out of sight from the control panel. He knows that each switch is correctly wired to one of the lights. He knows that all the bulbs are new and working, and he even knows the on and off position of the switches, but he doesn’t know which light is connected to each switch.

Fred’s boss is on the way out to the factory floor to see a demonstration of the machine, but Fred must determine how the switches and lights are wired before he can give a successful demonstration. He only has time for one trip down to the far end of the machine where the lights are mounted. How can Fred determine which switch controls each light in a single trip without anyone to help him?