Originally posted by Chrismo
As I am at my wits end trying to figure out the 2 switch problem, I thought I'd post one of my own. Can't remember where I got this from but it is one of my favourites...
A man has three sons. He lines them up so that the eldest (and tallest) is at the back looking down on the middle son, who in turn, is looking down on the youngest (and smallest) son ...[text shortened]... ought, the smallest son tells him correctly what colour he his wearing. What colour was it?
If the youngest and the middle son both are wearing red caps, the old one would know that he has a blue cap.
Cause the old one doesn't come with an answer of which cap he is wearing, the middle and the youngest son, know that they have two blue caps or a red and a blue cap.
So if the middle son could see a red cap on the young boy, he would know he had a blue cap. But if he sees a blue cap, he can't decide which colour his own cap is.
When he neither come with an answer, the youngest boy can conclude his cap is blue, cause if is was red, one of the others would already have answered.