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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 :p
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.Quote:
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. :hand:Quote:
Originally Posted by Sapphire
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.
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.Quote:
Originally Posted by billl
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?
Was it the Maid? Because the post is not delivered on Sundays?
:hurray: That is the one :D
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?
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?
Because on Mars they'd be marsquakes.Quote:
Originally Posted by prendrelemick
Assuming I'm right - and if I'm not, skip this next one until I do get one right, the question is:
What connects the following...?
Toledo, émigré, Miami, alfalfa, Esso, Motorola, spaghetti and dildo
Any takers?Quote:
Originally Posted by MarkBastable
All words have at least 2 letters which are the same:
Toledo - o
émigré - é
Miami - m (and i)
alfalfa - l (f and a)
Esso - s
Motorola - o
spaghetti - t
dildo - d
I thought about that too but I am hoping that there is something more -deeper and earth-shattering- to the puzzle, you know?Quote:
Originally Posted by Sapphire
:smilewinkgrin:
:lol: I know... it is just that I can not find it :wink5: So I figured I should just state the obvious :angel:
:lol:Quote:
Because on Mars they'd be marsquakes.
Well am not quite sure but i guess coz earth is the only blue planet i.e the only planet that has water.. and so this water causes some thunderstroms underground .. breaks down things under... Hence makes the earthquakes .. !Quote:
Originally Posted by prendrelemick
That is what some philosophers believe in .. like the Greek philosopher Democritus .. I read it somewhere .. so am not sure if its correct .. After all its just a hypothesis.
Nope. It's more lateral than that. And more fun.Quote:
Originally Posted by Sapphire
Last syllables are the musical notes?
Toledo, émigré, Miami, alfalfa, Esso, Motorola, spaghetti and dildo
Yep. The notes of a scale, in fact.Quote:
Originally Posted by Scheherazade
Damn - it usually takes longer than that.
That must be it :D
Smart :)
A quick one:
Which is the odd one out?
409 - 715 - 265 - 708 - 283 - 742
It's bad luck answering these, because then you have to come up with a new one.
maybe.. just maybe the 409:DQuote:
Originally Posted by Scheherazade
409 is the only trio of numbers that features an enclosed space in the written symbol for each of them (maybe that's why it stood out...).
So that is two against one ..Quote:
Originally Posted by billl
Way do go Bill:thumbsup:
Comman Scher . .. tell us we r right - hehehe
No, it is not 409.
It is a little more complicated than visual features of the numbers given.
It must be 708 then. The individual digits in the others all add up to 13, but this adds up to 15. ;)
Correct!Quote:
Originally Posted by Silas Thorne
Ah...I'll have to think of something then....I'll try not to be too long...
Got it! This is a fun one. Try to do this without an online search. It will be fun. :)
What English word is nine letters long, and can remain an English word at each step as you remove one letter at a time, right down to a single letter. List the letter you remove each time and the words that result at each step.
IQuote:
Originally Posted by Silas Thorne
in
sin
sing
sting
string
staring
starting
startling (9 letters)
I got stuck on the "a/an" path for a while.
Next:
A piggybank contains £7.37. It is made up of four different denominations of coins and the largest denomination is 50p. There is exactly the same number of each coin. How many of each coin is there and what are their values?
No takers?Quote:
Originally Posted by Scheherazade
I have to find out the english coin denominations first.:smilielol5:
:goof:Quote:
Originally Posted by papayahed
Sorry about that!
1p, 2p, 5p, 10p, 20p, 50p, £1 and £2.
Here's the coin denomination for British currency 1 2 5 10 20 50 (also, 25, I guess?).
I used brute force, and tried adding groups of four of these numbers and then dividing 737 by their sum. Finally, I got this:
737 divided by (50+10+5+2) = 11
So, the piggybank contains 11 each of 50p, 10p, 5p, and 2p coins. I stopped checking once I found this answer, so I can't say for sure if there's not another answer.
No 25p here.Quote:
Originally Posted by billl
11 is the answer I have got as well, Bill.Quote:
So, the piggybank contains 11 each of 50p, 10p, 5p, and 2p coins. I stopped checking once I found this answer, so I can't say for sure if there's not another answer.
Your turn! :)