A Paradox to Solve (quote)

~~The Unfan~~ · 09-28-2008, 08:16 PM

Its simple math. I have seen 21 but I've known the answer to this question since around 5th grade.

~~Fyrenza~~ · 09-28-2008, 08:17 PM

thats what i get for not watching tv

right you are UnFan

want another one?

RUPERT · 09-28-2008, 08:17 PM

Quote:

Originally Posted by RUPERT

THIS IS RIDICULOUS!

OK, SO YOU HAVE 3 BOXES ON A TABLE.

TWO BOXES CONTAIN VOUCHERS FOR DOG****, ONE BOX CONTAINS A VOUCHER FOR A MEDIEVAL CASTLE. (OBVIOUSLY YOU WANT THE FRICKIN MEDIEVAL CASTLE).

SO YOU PICK A BOX AT RANDOM AND YOU CLUTCH IT TIGHTLY TO YOUR CHEST.

YOU ARE THEN GIVEN THE OPTION TO OPEN UP ONE OF THE 2 BOXES ON THE TABLE, (THE TWO THAT YOU DIDN'T PICK), AND SEE WHAT'S INSIDE.

OOH. WELL WHADD'YA KNOW, IT'S A VOUCHER FOR DOG****.

SO NOW YOU'RE LEFT WTH JUST 2 UNOPENED BOXES. ONE UNOPENED BOX IS STILL ON THE TABLE AND ONE UNOPENED BOX IS BEING TIGHTLY CLUTCHED TO YOUR CHEST.

ONE OF THESE BOXES CONTAINS THE CASTLE VOUCHER, AND THE OTHER CONTAINS THE DOG**** VOUCHER.

...HOW CAN THE ODDS OF PICKING THE MEDIEVAL CASTLE BOX BE ANYTHING OTHER THAN 1-IN-2, REGARDLESS OF ANY LAST MINUTE SWITCH??

Can you tell me where I'm going wrong please

Wifey Boozer · 09-28-2008, 08:21 PM

You have one post.

RUPERT · 09-28-2008, 08:22 PM

that doesn't make me any less of a person

Will you help me to understand?

~~Fyrenza~~ · 09-28-2008, 09:08 PM

by switching you double the probability of finding the car voucher from 1/3 to 2/3. Switching is only not advantageous if you initially choose the 'right' box, which happens with probability 1/3.

With probability 1/3, you initially choose one of two 'wrong' boxes; when the other 'wrong' box is opened, switching yields the 'right' box with more certainty. The total probability of winning when switching is thus 2/3.

cardboard adolescent · 09-28-2008, 09:08 PM

Ok, when you know nothing about the situation each box has a 1/3 chance of containing what you want.

So, to start, it looks like this: 1/3, 1/3, 1/3
then you pick a box, so now you have 1/3 chance of having it right, 2/3 that it's one of the other boxes.

when you reveal what's inside of one of the other boxes, there's still a 2/3 chance that you made the wrong decision, but now that entire 2/3 rests on the box that hasn't been eliminated, since you know it can't be the other one. so now your odds are 1/3 that you have the right box, and 2/3 that it's the other one. so you should switch.

cardboard adolescent · 09-28-2008, 09:11 PM

/redundancy

that's not really a paradox anyway, here's a fun paradox:

consider a set of all sets which do not contain themselves as a member. would this set contain itself?

or

the next statement is true:
the previous statement is false

~~Fyrenza~~ · 09-28-2008, 09:34 PM

Quote:

Originally Posted by cardboard adolescent

/redundancy

that's not really a paradox anyway

ok mr smarty pants

it was a paradoxical puzzle

are we happy now?

Wifey Boozer · 09-28-2008, 10:00 PM

If this sentence is true then Santa Clause is real.

THAT's a paradox.

09-28-2008, 08:21 PM	#14 (permalink)
Wifey Boozer Meanie McFeany Join Date: Aug 2008 Location: Troy side'ah the dirt, NY Posts: 455	You have one post. __________________ ... Stalin had a *FANTASTIC* moustache. Formerly known as the Prime Minister of Spain. [backintheubbr]

09-28-2008, 10:00 PM	#20 (permalink)
Wifey Boozer Meanie McFeany Join Date: Aug 2008 Location: Troy side'ah the dirt, NY Posts: 455	If this sentence is true then Santa Clause is real. THAT's a paradox. __________________ ... Stalin had a *FANTASTIC* moustache. Formerly known as the Prime Minister of Spain. [backintheubbr]

09-28-2008, 08:16 PM	#11 (permalink)
~~The Unfan~~ Account Disabled Join Date: Dec 2006 Location: Methville Posts: 2,116	Its simple math. I have seen 21 but I've known the answer to this question since around 5th grade.

09-28-2008, 08:17 PM	#12 (permalink)
~~Fyrenza~~ Account Disabled Join Date: Sep 2008 Location: high above the Republic of Texas Posts: 216	thats what i get for not watching tv right you are UnFan want another one?

09-28-2008, 08:22 PM	#15 (permalink)
RUPERT Groupie Join Date: Sep 2008 Posts: 6	that doesn't make me any less of a person Will you help me to understand?

09-28-2008, 09:08 PM	#16 (permalink)
~~Fyrenza~~ Account Disabled Join Date: Sep 2008 Location: high above the Republic of Texas Posts: 216	by switching you double the probability of finding the car voucher from 1/3 to 2/3. Switching is only not advantageous if you initially choose the 'right' box, which happens with probability 1/3. With probability 1/3, you initially choose one of two 'wrong' boxes; when the other 'wrong' box is opened, switching yields the 'right' box with more certainty. The total probability of winning when switching is thus 2/3.

09-28-2008, 09:08 PM	#17 (permalink)
cardboard adolescent ;) Join Date: Nov 2005 Location: CA Posts: 3,503	Ok, when you know nothing about the situation each box has a 1/3 chance of containing what you want. So, to start, it looks like this: 1/3, 1/3, 1/3 then you pick a box, so now you have 1/3 chance of having it right, 2/3 that it's one of the other boxes. when you reveal what's inside of one of the other boxes, there's still a 2/3 chance that you made the wrong decision, but now that entire 2/3 rests on the box that hasn't been eliminated, since you know it can't be the other one. so now your odds are 1/3 that you have the right box, and 2/3 that it's the other one. so you should switch.

09-28-2008, 09:11 PM	#18 (permalink)
cardboard adolescent ;) Join Date: Nov 2005 Location: CA Posts: 3,503	/redundancy that's not really a paradox anyway, here's a fun paradox: consider a set of all sets which do not contain themselves as a member. would this set contain itself? or the next statement is true: the previous statement is false