Challenge - Solve this Riddle if you can!

last SG · 2006-04-28T01:33:15+00:00

All i got to say is.. ORD LOHHH!!!

UltimaOnline SG

Inspector Craig of Scotland Yard was called to Transylvania to solve some cases of vampirism. Arriving there, he found the country inhabited both by vampires and humans. Vampires always lie and humans always tell the truth. However, half the inhabitants, both human and vampire, are insane and totally deluded in their beliefs: all true propositions they believe false, and all false propositions they believe true. The other half of the inhabitants are completely sane: all true statements they know to be true, and all false statements they know to be false. Thus sane humans and insane vampires make only true statements; insane humans and sane vampires make only false statements. Inspector Craig met two sisters, Lucy and Minna. He knew that one was a vampire and one was a human, but knew nothing about the sanity of either. Here is the investigation:
Craig (to Lucy): Tell me about yourselves.

Lucy: We are both insane.

Craig (to Minna): Is that true?

Minna: Of course not!

From this Craig was able to prove which of the sisters was the vampire. Which one was it?

ditzy SG

Can you kindly post the answer with it so you don't have to use your clones? Laughing

icYwATeR SG

Mr. Green

S_T_F_U SG

Laughing can i have the answer pls? dun wanna guess the riddle. Embarassed

DriftingGuy SG

Lucy is the vampire, minna is the human. Laughing

Lucy's statement: we both are insane
Minna's statement: we are not both insane.

There are a total of 4 scenarios:

a) Both are insane.

In this case, Lucy tells the truth: So she must be an insane vampire. Therefore Minna is a human. But minna must be insane as well. Minna is lying when she say both not insane. So she is insane human, so she lies.

This is consistent, so lucy is insane vampire, minna is insane human. Laughing

b) Lucy is insane, minna is sane.

In this case, Lucy is lying when she say both insane. Since lucy is lying and insane, she must be insane human. But then minna should be vampire then. But minna is telling the truth and is not insane. This is a contradiction cos normal vampires should not tell the truth

So lucy cannot be insane human, minna cannot be sane vampire
Cool

c) Lucy is sane, minna is insane.

Similary like b, In this case, Lucy is lying when she say both insane. Since lucy is lying and sane, she must be sane vampire. But then minna should be human then. But minna is an insane human and yet she tells the truth so contracdiction again Laughing

So lucy cannot be sane vampire and minna cannot be insane human

d) Both lucy and minna is sane

Lucy is sane and is lying. So Lucy must be a sane vampire. Minna is then the human. Minna is telling the truth when she said lucy is wrong. So Minna is the sane human which is consistent.

So lucy is sane vampire and minna is sane human.

Conclusion, both are either insane or both are sane. Ultimately Lucy is vampire and minna is human
Mr. Green

Any flaws please tell me.. and yes i am that boliao to type all this out Laughing

UltimaOnline SG

100/100 marks! Very clear working. You're a Mathematics major who studied Logic, eh? Nice work! Smile

DriftingGuy SG

Nah... to be honest this doesnt require a maths major to solve.. and i am sure there are much faster, clearer ways to solve... and I was really sick of mugging so i can post all that Laughing

pwnz0r SG

I solved it.. Economics grad.. Similar to game theory.

dinky1409 SG

Lucy Insane vampire and Minna Insane human. It is consistent with the riddle.

Lucy Sane vampire and Minna Sane human. (If the truth is both are sane instead of the truth only one of them being sane and the other insane)

Yea bottom line Lucy is vampire and Minna is human. But whether they are insane or sane needs more clarification on the actual truth.

newmanmback SG

you must understand that picking on 2 characters alone is insufficient at all to eliminate vampirism...providing a correct (or rather, logical) answer does not prove that u will be the right hand or justice and will ever free mankind from this deadly plague. you may just happened to pick on a grouchy human who tells the truth (he is a bad guy) and a vampire whi is very cunning to tell the truth (through a lie) about him being a turncoat undead who is 'insane'.

the logic answer and the studies of psychology for both humans and monsters (of human relation/ nature) will prove that a town half infested by vampires will long be free of any form of life since all shall be the prey and meals for the blood thirsty undead.

there are once again many answers to this and all can be provided from a brain that thinks and have ideas of its own:-

1) both are sane vampires (they provide answers to confuse Craig)
2) both are humans (they do not get along well and one is confusing Craig)
3) both are vampires (one happened to be 'insane')
4) Craig is the vampire (coz he won't satnd a chance distroying the undead the moment he stand in town he's owned!)

Mr. Green

tt3 SG

lucy la… where gt ppl go tell other ppl tt they r insane… siao ah…

[email protected] SG

lucy is the vamp, minna is human. no matter which way u put it, eg:

lucy insane, minna insane, hence true, minna would be a insane human, making lucy an insane vamp.

there are a few scenarios because lucy can be lying about BOTH of them being insane or either one of them being insane, as well as the truth being both of them are insane.

matleep SG

i can explain faster,

lucy if human and sane will not say she insane.
Lucy if human and insane will not say she insane. Cos she thought she is sane

so lucy is vampire

Texcoco II SG

Sounds like a probabilty method to me

digicharat SG

betty is the vampire. lulu is the human.

azurewaves SG

maybe he just looked at their teeth when they were talking... ^^

BillyBong SG

The answer Minna gives to Craig will always be wrong. So Lucy was telling the truth.

Duh!

bksianzz SG

vv easy what this riddle….

newmanmback SG

for me to find the truth very easy…...just interview both of them in the broad daylight and under the sun, add a pool of holy water blessed by the priests and tie them both up by the crucifix, place their hands on the holy bible and leave them there with food and water but no human blood after a while u will know..the secure and most accurate ways of interrogation ….. as for speeches and words and reactions from common sense … who can’t do it…but its minions of the drakness we dealing with here ….. common sense can’t really apply

Fey Mae SG

the riddle is quite easy actually. Embarassed