How smart are you?

[Hellbent]

[edit] I have edited this slightly to make it more clear for the less astute Doomers.... :)

Consider the following claim:

“If a card has a ‘D’ on one side, it has a ‘3’ on the other.”

You are presented with the following cards, and are asked to verify this claim. How many cards do you need to turn over to verify the claim?

D F 3 7



If you are still struggling with what the puzzle is asking click here: http://schmolze.com/Puzzle.doc

[Liam]

All of them? I dunno. It's late. Ask me tomorrow.

[Sharessa]

665

[IMJack]

Hellbent said:

Consider the following claim:

“If a card has a ‘D’ on one side, it has a ‘3’ on the other.”

You are presented with the following cards, and are asked to verify this claim. How many cards do you need to turn over?

D F 3 7

Three. The claim is verified if the D has a 3 on the back and the F and 7 do not have a D on the back.

It does not matter what is on the back of the 3 card, as the claim says nothing about it.

[GooberMan]

I say only one. The question is only asking about the card D, not any of the others. Flipping over the D card will either verify the claim or prove it to not be true. You could be presented with 50 cards, only one of which has a D on the front of it, and to prove the statement “If a card has a ‘D’ on one side, it has a ‘3’ on the other.” you only need to flip over the D card to verify that stement, not every single card in the lineup.

EDIT: Just thinking about what IMJack said. it really depends on which way up the cards were dealt. He said that you wouldn't have to worry about what was on the back of the 3, but what if the 3 was dealt back-side up?

[læmænt]

IMJack said:

Three. The claim is verified if the D has a 3 on the back and the F and 7 do not have a D on the back.



It does not matter what is on the back of the 3 card, as the claim says nothing about it.

congrats

[Lüt]

IMJack said:

It does not matter what is on the back of the 3 card, as the claim says nothing about it.

...except that there should be a D on the other side.

[Fredrik]

Two

[mmnpsrsoskl]

Actually you would need to flip over all 4 cards, because the 3 card might not have a D on the other side, and the f and 7 cards might. The D card might not also have a 3 so you have to check all 4.

It does not matter what is on the back of the 3 card, as the claim says nothing about it.

GooberMan is right about what he said.

[Erik]

it's 3

[Sharessa]

I'd check all of the cards, just because I'm so paranoid and anal retentive like that.

[Spike]

one.
murr.

[Fredrik]

Some things are unclear.

How are the cards placed? Are they hung in the air? If so, I don't need to turn them, I can simply walk around and look from the other side. I may also have a mirror behind the cards that lets me view both sides at once.

If the cards are lying on an object such as a table - are the cards half transparent? Is the object on which they lie half transparent?

If the cards are opaque to normal light - is it possible to see the other side using infrared or ultraviolet light?

Assume that the cards and the labels are in different materials, these will have different physical properties. It may for example be possible to find out what the other side says by measuring the spacetime interference caused by the card's gravity.

Are we speaking of two-dimensional cards in a three-dimensional space or two-dimensional cards in a four-dimensional space? Or perhaps three-dimensional cards in an eleven-dimensional space?

Are the cards located within a black hole?

The question, as currently explained, can unfortunately not be solved correctly because there are too many factors left out.

I can provide a few possible answers though:

3

0

42

-6

2.7182818284590452353602874713527

[IMJack]

The claim is: “If a card has a ‘D’ on one side, it has a ‘3’ on the other.” Or, if you will, "a 'D' on one side implies a '3' on the other." You can't reverse the claim and say that a '3' on one side implies a 'D' on the other. Implication ops don't work that way. All the claim is saying is if there is a 'D' on either side of the card, and the other side is not a '3', the claim is false.

[Hellbent]

LOL@Fredrik.

If some of you are having trouble with the logistics of this puzzle, this may clarify things for you.

http://schmolze.com/Puzzle.doc

[Lord FlatHead]

Three cards. It doesn't matter what's on the back of '3', you just need to check if there's a 3 on the back of 'D', and wether or not '7' and 'F' have a D on them - in which case the claim would be false.

[nxn]

this isn't hard, it's just worded to confooze you.

[pritch]

quit fucking playing with gay cards and go download some pr0n like normal, healthy people :L

YES THATS RIGHT< TEH NEW SMILEY :L

YES, I KNOW IT SUX, THANK YOU. :L

[nxn]

that smily looks like he's paralyzed and drooling

I need a moose smily =\

[nxn]

The answere may very depending on what the question is asking. If the group only needs 1 card to have the D on one side and 3 on the other I'd check 2 cards (the D and the 3) incase one of them wasn't it. And if you need all the cards to be correct in order for the group to be valid I'd check 3, the D, F, and 7. The 3 does not matter since if it does have a D on the other side it won't make any difference and the same goes if it didn't have a 3 because the info states that if a card has D on one side it has to have a 3 on the other, and not the other way around.

[Hellbent]

I guess at this point I should say that one person asnwered correctly.

[JavaGuy]

I could just... walk away and not let the whole game bother me. Why not let the dealer muddle about on his own for a while? By the time I come back, he probably won't want to play the game anymore, and we can do something more useful and interesting.

[stphrz]

D F 3 7

Notice the F card. It has a D to it's left. It has a 3 to it's right. A D on the left side, a 3 to it's right side. Why would you have to check either face of the cards. No where in the question does it say there is a character on both faces of the cards. The answer is staring right at you.

none

=P

[nxn]

stphrz said:

No where in the question does it say there is a character on both faces of the cards.

Hellbent said:

Consider the following claim:

“If a card has a ‘D’ on one side, it has a ‘3’ on the other.”

You are presented with the following cards, and are asked to verify this claim. How many cards do you need to turn over?

D F 3 7

you sure about that?

[stphrz]

orion said:

you sure about that?

'Course not :P (did you note the sarcastic '=P'?) The puzzle is worded poorly or out of context. Here is a fact: The statement "If a card has a ‘D’ on one side, it has a ‘3’ on the other." can only be proved true by turning over all the cards (assuming there are no other cards in existance except those four). What if the F card has a 3 on the other side? What if the 7 has a D on the other side?

[nxn]

stphrz said:

'Course not :P (did you note the sarcastic '=P'?) The puzzle is worded poorly or out of context. Here is a fact: The statement "If a card has a ‘D’ on one side, it has a ‘3’ on the other." can only be proved true by turning over all the cards (assuming there are no other cards in existance except those four). What if the F card has a 3 on the other side? What if the 7 has a D on the other side?

Nope didn't pick up on the sarcasm trail, and yes I agree it's worded poorly, if you check the doc he linked to though they'll have a different example, I looked at it and it did make more sence.

[Captain Skippy]

TWO CARDS!!!!!!!!!!!!!!!!!!!!!!!!!!

[Hellbent]

quote:
--------------------------------------------------------------------------------
orion said:
you sure about that?
--------------------------------------------------------------------------------

Stphrz said 'Course not :P (did you note the sarcastic '=P'?) The puzzle is worded poorly or out of context. Here is a fact: The statement "If a card has a ‘D’ on one side, it has a ‘3’ on the other." can only be proved true by turning over all the cards (assuming there are no other cards in existance except those four). What if the F card has a 3 on the other side? What if the 7 has a D on the other side?

If the F has a 3, why does that matter? The problem clearly states to verify the claim: “If a card has a ‘D’ on one side, it has a ‘3’ on the other.” If the F had a 3 on the back of it, would that verify the claim?

[nxn]

yeah, but let's say the 3 had an F on the back, that would disprove it since a card with a D has to have 3 on the back and the other way around. Fuck, it's just not clear enough. The End.

[nxn]

Actually, no The End just yet. The answere is 2, you need to turn over the D to see if there's a 3 on the back and you need to turn over the 3 to see if there's a D on the back.