Are the gay mathematicians excluded? 
No, only players of gay rugby. 
well obviously you go in the white door and not the red one…
but if you wanted to be sure you could ask either guy, “what would the other guy say is the good door?”
then you go in the other one…
sorry i’m a top-down processor…
ahem… Hey guy, would the other guy say the left door is the good one?
if he says yes, go in the right one, if he says no, take the left one.
Why don’t you open them both and see what’s behind them? I mean, there’s no one forcing you to go through the doors if you open them.
Or just torture it out of them. Or just say “blow this” and go home. Or kill one, steal his skin and go back to his home. Worked for Hannibal lector. That’s the trouble with these riddles, no points for thinking outside of the box.
You have to be a bit more than not-dumb to solve this.
The argument:
If a card has a vowel on one side, then it has an even number on the other.
Q: Which of the back of the four cards would you have check to see whether there is an instance where this argument is invalid?
Information available to you:
The cards have a letter on one side, and a number on the other.
Card 1:
[size=150]E[/size]
Card 2:
[size=150]K[/size]
Card 3:
[size=150]4[/size]
Card 4:
[size=150]7[/size]
card 4
You’d need to check two cards. And if you two were the same person, then you’d be right.
You’d need to check the card with a vowel on the top side because if the backside isn’t an even number then that’s obviously an instance that would invalidate the argument. You don’t need to check the second card because it’s a consonant, and so it doesn’t matter to the argument what the number on the back is. You don’t need to check the third because it’s representative of the consequent of the argument and it is true, which means it’s irrelevant what the backside of it is (ie if the consequent is true, it doesn’t matter what the truth value of the antecedent is, the argument will be valid). You would need to check the fourth card because it’s an odd number, which means that if the backside of it is a vowel, then that would be an invalidating instance. Thanks for playing.
Here’s another one, straight from my epistemology book, in the section raising skeptical doubts as to our rational faculties, to then infer something else in an ol’ cartisian style.
Information given to you:
Linda is 31 years old, single, outspoken, and very bright. She majored in philosophy in college, and was heavily involved in cases of discrimination and social injustice.
In order of probability, rank from one to three, with 1 being the most probable and 3 the least, the following three statements:
- Linda is active in the feminist movement.
- Linda is a bank teller.
- Linda is a bank teller and is active in the feminist movement.
xzc, you have to check card 1 because if there is something other than an even number on the other side then the rule would be broken, you also have to check card 4 because if there is a vowel on the other side then the rule will also have been broken.
and for the second question, though i’m not sure i’m right, but there seems to be no way to make solid inferences, and rating probability is not the most logical activity.
Since “bank teller” is in no way related to any of the iformation given about linda, i conclude that the first statement is the most probable.
even though feminists don’t need to take philosophy courses it seems like it would assist on the path toward becoming a feminist
The next most probable thing is that linda is a bank teller, because the probability of her being a bank teller AND a feminist is less than the probability of each qualty seperatly.
so i wouldn;t change the order of the statements, i think they are already in order beginning with most probable…
in reality 1 and 2 could have the same probability rating, and 3 is obviously lower since two combined risks equal a greater risk.
Maybe this one is a little too well known…but apparently first graders have an easier time with this one than graduate students.
Find the next letter in the sequence:
O T T F F S S E _
Since you can’t actually eat feminist principles, I’d say it’s more likely she has a job. But really its all inferrential. So, screw it double-jeopardy - they are all equally likely/unlikely.
The other with the cards is a classic ‘social contract’ abstract version from, weeeelll, before all you guys, and me, were born. You need to check two cards:
E (P) K (notP) 4(Q) 7(notQ)
So logically - P and notQ must be checked ie: E and 7.
The flip version which everyone finds easier is a human context:
“You work in a bar. No-one under 21 is allowed to drink alcohol”.
Four guys:
drinking a beer (P) drinking coke (notP) 25yrs old (Q) 16yrs old (notQ)
Who do you check…?
No-one 'nos nothing never naturally.
000
111
222
333
444
555
666
777
888
999
101010
you can add any mathematic nomenclature you like but every line must come out 6, nor can you use the same exact method twice.
except for the last option.
the likelynes of being a feminist and a bank teller is lower than being a bank teller or a feminist.
Nah. Who knows? x Who knows? = Who knows?
the shadow knows
-Imp
when we’re talking about the sheer probability that linda is a feminist, all you have to do is create an imaginary sample.
x out of y women are feminist in any given region (that includes linda).
Common sense tells us that x is not as great as y, and if you care to assume that there is at least 1 feminist in her region it is not zero.
Assuming there is at least 1 teller and that everyone is not a teller, the probability of being a feminist (not being zero and not beiing 100%) multiplied by the probability of being a teller (not being zero and not being 100%) is necessarily a lower percentage than either alone, making it the lowest probability.
in reality if she’s not a teller and not a feminist you can’t really say that the probability of her being either or is zero. there is simply no statistical data to use in this situation, i used something like the rule of the masses.
the cards have a number and a letter. card 2 has a k, therefore there is no vowel on the other side and you don;t need to check it…
The given information is supposed to make the option which says she’s a feminist political activist number one in terms of probability, and that she’s a banker number two. That she’s a (banker and a feminist) is automatically the least possible answer since if any of it’s conjuncts (either option one or two) are false, then the whole third one becomes invalid. For whatever reason people seem to think what tab said about the third one, and they’re exactly the people those who came up with this example had in mind for their “people come to irrational conclusions” premise. No offense tab, but you just got pwned by the nerds who came up with this weak ass epistemological skeptical theory. 
You’re right. I had to put that information in ps, just for this reason.