That’s A Bit Odd

The Problem:

Back in the Neolithic Times, when numbers were small and precious, an aging cave Elder wanted to choose an intelligent younger person to succeed him as leader.

He mixed up some pigment, and daubed simple numbers on each of the foreheads of the five ‘candidates’ he felt most likely to be suitable. He told them that he had given three of them odd numbers and two of them even numbers, and he wanted them to tell him which type of number they had on their own forehead…

In fact, being a bit of a monkey, he had daubed odd numbers on them all!

After about half a day of puzzled peering and studied preening, one of the group slapped her forehead and shouted out, “Grog – grog, grog, grog!”, which meant “Odd –odd, odd, odd!”

How did she know?


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Last modified: June 18, 2007