Mind Games 4

A couple of puzzlers to test logic, language and lateral thinking skills - plus a befuddling optical illusion, the "checkershadow".


14. Switching on


An evil genius has locked you up in a two-room prison. In your cell, there are three electric switches in the “off” position. In the second room, you’re told, are three light-bulbs, turned off. Each is controlled by one of the switches.

You can’t see the light-bulbs: the interleading door is closed, and the room they’re in is completely sealed off, with no windows or other exits, and no way to peer inside.

Your captor shrieks, “You’re free to go – IF you can work out which switch operates each lightbulb! Here’s the catch: I’m going to let you go into the other room. But only once. When you come out, you must tell me exactly which light-bulb is operated by each of the switches.”

How do you escape the clutches of the light-bulb obsessed maniac? See answer

15. A most unusual paragraph

This is an unusual paragraph. I'm curious as to just how quickly you can find out what is so unusual about it. It looks so ordinary and plain that you would think nothing was wrong with it. In fact, nothing is wrong with it! It is highly unusual though. Study it and think about it all you want, but you still may not find anything odd. But if you work at it a bit, you might find out. See answer

Optical illusion

16. Checkershadow illusion:

Which is darker, square A or Square B? Are you absolutely sure? See explanation

- Compiled by Olivia Rose-Innes and Senora Sine Thirteen, Health24, July 2011

The checkershadow optical illusion was designed by scientist Edward H. Adelson.
Georges Perec, La disparition, 1969; translated as A Void by Gilbert Adair, 1994.
Ernest Vincent Wright, Gadsby, 1939.

Do you have a great brain teaser? Please send it to us; we choose the best ones to feature on Mind Games.

See more Mind Games

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