momusradar

I came across the following puzzle at God Plays Dice, who came across it at Fark:

FACTS:
There is a bus with 7 children inside of it
Each child has 7 rucksacks
In each rucksack there are 7 big cats
Every big cat has 7 small cats
Everything listed above is entirely in the bus
All objects are unique
There is no driver
Every child has 2 legs
Every cat has 4 legs

QUESTION:
How many legs are in the bus?

Although it did take me four attempts to solve it, I’m happy to be part of the 20% who got it right. As of this posting that percentage has dropped to 17%.

addendum February 27, 2008

As noted at God Plays Dice, the key to solving this problem is to fully grasp the facts.