It's a famous math problem, called the Monty Hall problem, Sapphire was close.
If you don't switch your probability of getting the prize remains 1/3.
If you do switch the probability is 2/3.
It's counter intuitive, but the laws of probability happen to be counter intuitive.
Think of the possibilities if you always pick 1.
Results if Switch/ Don't Switch
0 /cash
cash /0
cash /0
Mark Haddon's "The curious incident of the dog in the night" has that puzzle in it, (and the explanation)
The riddle from the Sphynx of Thebe
Which creature in the morning goes on four legs,
at mid-day on two,
and in the evening upon three,
and the more legs it has,
the weaker it be?
Remember, you'll be strangled by the Sphynx when you're unable to answer correctly
It is not too late, to be wild for roundabouts - to be wild for life
Wolfsheim - It is not too late
Studies show that only 13% of people get that question right on first encounter. The more options, (according to the studies over 7 doors is the point where most people intuitively grasp that you should always switch), the easier it becomes for people to grasp the concept. Our brains work in funny ways.Originally Posted by prendrelemick
Edit: I'd be more surprised if someone on this forum doesn't know the answer to the Sphynx's riddle.
Course if you get it right, you may kill your father and marry your mother.The riddle from the Sphynx of Thebe
Which creature in the morning goes on four legs,
at mid-day on two,
and in the evening upon three,
and the more legs it has,
the weaker it be?
Remember, you'll be strangled by the Sphynx when you're unable to answer correctly
Terry Pratchett in Pyramids has a wonderful breakdown of how the Sphinx got the riddle wrong: for the answer to be accurate, the question should have been something like 'What goes upon four legs for about half an hour in the morning, two for most of the day and three for twenty minutes or so in the evening?' The Sphinx goes away muttering that the riddle had always worked before and he couldn't understand why this victim had not only got away but had left him/her thoroughly confused and needing to find a new riddle.
Can we take this one as answered, and move on?
Yeah, if anybody has a new one, then they are the hero! C'mon, show us!
EDIT: Oh Yeah, SPOILER!!!! ...the thing in the 'Sphinx' riddle is a person. In the early "morning" portion of life, the person is crawling on all fours. Then, at their strongest and most vigourous, the person is walking and running on two feet. Finally, the older, weaker version must incorporate a cane, and is thus 3-legged.
This is maybe the most famous riddle of all time,
and it is part of the journey of a famous Greek King, for those out there who don't already know.
Last edited by billl; 11-04-2010 at 04:27 AM.
Of course if the child is being carried by his mum, or riding a horse, or being pushed in a 8 wheeled buggy by a nanny wearing roller skates, the permutations of legs, heads, wheels and tails become more complicated.
How about a little murder mystery?
A man was found murdered one Sunday morning.
His wife immediately called the police.
The police questioned the wife and staff and was given these alibis:
The Wife said she was in bed reading a book.
The Cook claimed she was cooking breakfast.
The Gardener claimed he was planting seeds.
The Maid claimed she was getting the mail.
The Butler claimed he polishing the silver.
The police instantly arrested the murderer. Who did it and how did they know?
It is not too late, to be wild for roundabouts - to be wild for life
Wolfsheim - It is not too late
Was it the Maid? Because the post is not delivered on Sundays?
~
"It is not that I am mad; it is only that my head is different from yours.”
~
That is the one
It is not too late, to be wild for roundabouts - to be wild for life
Wolfsheim - It is not too late
I am uploading an attachment for the next one (another one from my childhood).
Here is the question: At a church, the priest arranges the bags containing their gold as shown in the attachment and every morning and evening, he comes in to count them to make sure that none is missing.
He first counts vertically: 10 bags.
He, then, counts vertically up to the left end point of the cross: 10 bags.
And, finally, he counts again up to the right end point of the cross: 10 bags.
After much observation, a thief decides that he can beat the priest's method. He takes away two bags and changes the position of one. Next morning, when the priest comes and counts the bags again three times as mentioned above, he is satisfied as counts give the same results as usual: 10 bags.
Which bags did the thief steal and which one did he repositioned?
~
"It is not that I am mad; it is only that my head is different from yours.”
~
Take extreme left and right hand bags. Then move the top bag to the bottom.
Earthquakes are a very common occurence, yet ours is the only planet in the solar system that has them. Why?
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