[10 Min Test] - Riddles of IQ that train the Academic mind
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Sure, you can take the lazy shortcut and google the answers to these riddles, but hey, live a little, have the courage to honestly challenge your own mental prowess and academic competence in logic, eh? See if you can get all 5 questions correct within 10 minutes. Time yourself!
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Updated/Edited :
I initially thought of 'marking' the replies here and scoring them, all of them one-by-one; but as it turns out (and you can see this for yourself), the way the replies are posted, (eg. "solution already posted in riddles forum", instead of a proper explanation in your own words), it makes properly marking and scoring the replies quite difficult, if not impossible. Besides, I can tell you guys are having more fun discussing the riddles with each other, rather than just having your replies marked, and obtaining a score.
So to this end, I'll not 'mark' or score you guys, but instead, leave you to continue discussing and debating these rather brilliant riddles. Rest assured, these are not 'nonsense' riddles without answers; everyone of these 5 riddles are valid exercises in logic, IQ, mathematics and intuition.
Continue having fun!
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Number of Qns correct (must be within 10 minutes, and valid only if you're 100% honest with yourself) :
1 - U Cockonaden - 沒脸見人…呸!
2 - Ok lah just pass - ��強強�以.
3 - U Da Power - 好厲害哦!
4 - Legendary - 天下無敵 神話崛起
5 - Godlike - 以天下人之心為心 以天下人之�治天下
Q1 to Q5, In increasing order of difficulty :
1) The "Chicken" Riddle
A man bought a chicken for $8, sold it for $9, bought it back for $10, and sold it for $11. How much profit did he make?
2) The "Three Men & A Waiter" Riddle
Three men ate dinner at a restaurant. The bill came up to $30. Each paid $10. After they left the restaurant, the manager realized there was a mistake in the bill. The bill was merely $25. He sent a waiter with $5 to pay back the 3 guys, who had gone their separate ways. As the waiter ran after the 3 guys, he realized they had split up, and he thought to himself, "How the heck am I supposed to pay each person 5/3 dollars? Heck, I'll just give each guy a dollar each, and keep $2 for myself as tips!".
So each guy paid $10 - $1 = $9. Three guys paid $9 x 3 = $27 in total. Plus the $2 the waiter kept, that's $27 + $2 = $29. What happened to the missing dollar?
3) The BoyBoy-BoyGirl-GirlBoy-GirlGirl Riddle
You and a friend are standing in front of two houses. Your friend informs you, "In each house lives a family with exactly two children."
"For the family on the left, at least one of the two children is a boy", your friend tells you.
"The family on the right has a 7-year old boy, and they just had a new baby a month ago," he explains.
"Does either family have a girl?" you ask.
Your friend smiles, "Pick the family that you think is more likely to have a girl. If they do have a girl, I'll buy you dinner."
Which family should you pick, or is it the case that it does not matter? Explain using probability mathematics.
4) The "Monty Hall Goat Riddle" aka "Marilyn vos Savant and the Goats"
A thoroughly honest game-show host has placed a car (the winning prize) behind one of three doors. There is a goat (consolation prize) behind each of the other doors. You have no prior knowledge that allows you to distinguish among the doors. "First you point toward a door," he says. "Then I'll open one of the other doors to reveal a goat. After I've shown you the goat, you make your final choice whether to stick with your initial choice of door, or to switch to the remaining door. You win whatever is behind the door." Should you switch doors? Explain using logic, mathematics, or compelling intuitive arguments.
5) Inspector Craig Visits Transylvania
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?
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1) lets say the man got $12 at first. he bought chicken at $8 but sold at $9 so he has $13 at the end. Using the $13, he bought it at $10 and sold at $11 so he ended up with $14. $14-$12= $2 so he made $2?
2) dunno
3) the left house got 3 possibilities: elder boy-younger girl, elder girl-younger boy and elder boy-younger boy.
the right house got 2: elder boy-younger girl, elder boy-younger boy
so choose the house on left?
4)dunno
5)dunno
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2) the total paid by man is $27. total by resturant is $25. $2 is by waiter. your q include double counting
4) change for better odds. was covered in jokes and riddles forum
5) luck statement can only be made by insane vampire/sane vampire.
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1) simple addition, so give away question?
3) does this include adults?
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5) 2 possibilities:
Lucy: true, sane human or insane vampire
Minna: false, insane human or sane vampire
OR
Lucy: false, insane human or sane vampire
Minna: true, sane human or insane vampiresince one is a human and the other is a vampire, both are either insane or sane.
so, lucy: sane, human
minna:sane, vampire
OR
lucy: insane, human
minna: insane, vampire.
since both cases has minna as vampire, shes the vampire.
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Originally posted by UltimaOnline:
1) $1
2) If you divide $25 by 3, you get $7 each and remainder of $4, So if each pays $8, you get $1 in which one of them must pay. So with the remaining $5 each gets back $1. There is actually no missing dollar. It's the problem with the division of 25/3
3) The left side has a girl, because there is 1 out of 2 chance.
4) Stick with my choice
5) Minna
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1) 2 dolars
2) its mathematically impossible from the start. 25 dolars is not divisible by 3. The waiter took the 2 dlars as the change is not divisible. thats all.. they actually paid 28 dolars (plus tipps) instead of 27.
3) i would choose the right (NOT SURE)
4) switch (bet that the one u chose is wrong, much higher percentage than the one u chose is right)
5) lucy is the vampire..
as one is a human and one is a vampire. it would be impossible for one to be sane and teh other to be insane. so leaves it to be both sane or both insane.thus i can conclude that lucy is a vampire either ways.
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Originally posted by ohnoez!:
5) 2 possibilities:
Lucy: true, sane human or insane vampire
Minna: false, insane human or sane vampire
OR
Lucy: false, insane human or sane vampire
Minna: true, sane human or insane vampiresince one is a human and the other is a vampire, both are either insane or sane.
so, lucy: sane, human
minna:sane, vampire
OR
lucy: insane, human
minna: insane, vampire.
since both cases has minna as vampire, shes the vampire.
dude, impossible for insane human to say :" we are both insane"impossible for sane human to do that too...
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Originally posted by ohnoez!:
1) lets say the man got $12 at first. he bought chicken at $8 but sold at $9 so he has $13 at the end. Using the $13, he bought it at $10 and sold at $11 so he ended up with $14. $14-$12= $2 so he made $2?
2) dunno
3) the left house got 3 possibilities: elder boy-younger girl, elder girl-younger boy and elder boy-younger boy.
the right house got 2: elder boy-younger girl, elder boy-younger boy
so choose the house on left?
4)dunno
5)dunno
for answer 3) don't you have to double count the boy-boy probability?
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lol anyhow do one..
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actually for 3, both has the same probability however, to scrutinise,
the probability for one of the 2 to be gals is, 50 perecnt as one is definetely a boy, 1- 1x1/2 is also 50 percent
and the probability for the right to be a gal is 50%
so its impossible to solve this qn
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Originally posted by elementalangel:
1) 2 dolars
2) its mathematically impossible from the start. 25 dolars is not divisible by 3. The waiter took the 2 dlars as the change is not divisible. thats all.. they actually paid 28 dolars (plus tipps) instead of 27.
3) i would choose the right (NOT SURE)
4) switch (bet that the one u chose is wrong, much higher percentage than the one u chose is right)
5) lucy is the vampire..
as one is a human and one is a vampire. it would be impossible for one to be sane and teh other to be insane. so leaves it to be both sane or both insane.thus i can conclude that lucy is a vampire either ways.
for 5) if lucy is insane vampire and mina is sane human, it will still work out. right answer, wrong reasoning -
erm read my explanation only both sane or both insane so...
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if it would be that both lying or both saying the truth , it wont work out..
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ok i got it... aha but i worked it out that way...
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Originally posted by elementalangel:
ok i got it... aha but i worked it out that way...
so by your logic ==> Lucy sane human mina sane vampire
==> Lucy sane vampire mina sane human
==> Lucy insane human mina insane vampire
==> Lucy insane vampire mina insane human.
since both is sane or insane. how does this help in determining lucy is the vampire?
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see how they answer lo
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1) total profit made, i believe is $2.
2) this question answer until sian liao. so i just skip.
3) this one i'm not sure. i think maybe is the right one.
4) switch doors because your chance of getting it right is higher!
5) Minna is the vampire.
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1)2 but depends on whether you consider his time spent on the trades.
2)what missing dollar? Nothing is missing.
3) if you define girl as female and the families are normal, then both will have. otherwise not difference. 4) No diff. 5) minna.
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Qn(5)
Craig (to Lucy) :Tell me about yourselves.
Lucy : We are both insane.
Craig (to Minna) : Is that true?
Minna : Of course not!
sane human and sane vampire will answer we are sane. Vampire say sane so that it appears as a sane human.
insane human and insane vampire will answer we are sane or insane ==> cannot differentiate reality.
Therefore, Lucy is confirmed insane.
Minna said "Of course not!" ==> Lucy and her are sane==> Minna lied.
Only vampire lies, so Minna has to be vampire.
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Originally posted by Uncertain:
Qn(5)
Craig (to Lucy) :Tell me about yourselves.
Lucy : We are both insane.
Craig (to Minna) : Is that true?
Minna : Of course not!
sane human and sane vampire will answer we are sane. Vampire say sane so that it appears as a sane human.
insane human and insane vampire will answer we are sane or insane ==> cannot differentiate reality.
Therefore, Lucy is confirmed insane.
Minna said "Of course not!" ==> Lucy and her are sane==> Minna lied.
Only vampire lies, so Minna has to be vampire.
wouldn't sane vampire say they are insane?
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Originally posted by skythewood:
wouldn't sane vampire say they are insane?
haha anyway I saw the answer. We cannot work this question out by logic as it is a mathematical paradox.To answer your question in my perspective, I will say a sane vampire won't try to act abnormal by saying we are insane. He will try to act in a way which a sane human will react so as to hide his identity.
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1. $2
for example at first i got $8, i bought it the first time and got no money left. then i sell it for nine dollar... so now i have $9.
i go buy the chicken back at $10, so now i have -$1, after i sell it for $11, i got $10...
10 - 8 = 2... so $2...
2. if we solve it in another way, $30 -$25 = $5
and the waiter took $2, so it makes it $27, 9 x 3 = 27.... and we add up the 3 dollar given out to the 3 men, so it is 27 + 3 = 30... there is no missing number...
another factor is this... 5 divided by 3 is 1.6666666666666666... and so on..
therefore, there is no exact number for it...this is all i can think of question 2... tho i think i am wrong... bleh
3. both of them are the same... it doesnt matter tho age and these all as when both family already had 2 children... without the consideration of having another baby...
therefore it is a 50% 50% for both family..
4.i dun understand why forumners all say change... i dun get it tho... i think it is the same whether to change anot...
5. cant tell.... since both have the possibilities
so tell me my score?
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UltimaOnline :
As I updated my original post, I won't be giving out scores anymore. But since you specifically asked... your score (already considering your next post below) is 2 out of 5.
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btw correct my question 2...
9 x 3 = 27... and this is the money paid by the 3 men assuming the price is 25 instead of 27 since the waiter took the $2... 27-25=2....
and the $3 left is taken by the change of the 3 men...
so i am sure i am correct bout this....
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