Question

Fun logic puzzle for today.
There are 111 people in a competition. The competition has 4 boxes and 4 jewels. Each box is identical and is completely opaque (i.e. you cannot see inside the box once it is closed). The jewels are all different: diamond, ruby, emerald and topaz. Everyone in the competition knows this. The host (who is NOT one of the 111 taking part), places one jewel in each box and then seals the boxes and writes a letter on each box: A, B, C and D - all done WITHOUT any of the 111 competitors watching. The competitors are then asked to guess which jewel is in which box.

Answer 1

- 9 people get all 4 of their guess wrong
- 15 people guess exactly one jewel correctly
- 25 people guess exactly 2 jewels correctly

How many people:
a) guess exactly 3 jewels correctly
b) guess exactly 4 jewels correctly

Answer 2

Oh dear.

Answer 3

:)

Answer 4

this is based purely on logical reasoning - no complicated maths involved. :)

Answer 5

I am bowing out, I shall no longer strain my brain for this :P

Answer 6

fair enough - but I warn you - you WILL kick yourself when you find out the answer. :)

Answer 7

Well there ARE 64 people left.... But how are you supposed to know which is which?

Answer 8

64?

Answer 9

62.....

Answer 10

I meant 62

Answer 11

Sorry, did it in my head, mental math is not so good :p

Answer 12

:)

Answer 13

o.o.... I don't know how your supposed to know, unless there is some pattern.

Answer 14

no patterns involved - just pure reasoning :)

Answer 15

So, just to make sure I understand, there is no mathematical way to do this, it's just reasoning.

Answer 16

you don't need to use any particular mathematical method - just pure reasoning should get you to the answer.

Answer 17

pay close attention to the question and to what is being asked for...

Answer 18

Wow. I really don't know. I'll probably be upset for not thinking of it once you tell us, but I give up for now. When will you tell us??

Answer 19

I'll give it another hour - if no one solves by then I'll post the solution.

Answer 20

HINT: Pay close attention to the word EXACTLY

Answer 21

a)0 b)62

Answer 22

a 42
b 20

just guessing? xD

Answer 23

@ig0p0g0 wins! :)

Answer 24

wat

Answer 25

it is impossible to guess EXACTLY 3 correct - the remaining 4th jewel MUST also be correct. :)

Answer 26

Please explain??

Answer 27

*facepalm*

Answer 28

Ok now I feel stupid :(

Answer 29

@UsaChan<3 I explained above - hopefully you understood the reasoning.

Answer 30

@thomaster YOU are anything BUT stupid my friend! :)

Answer 31

Oh for the love of god....

Answer 32

:D

Answer 33

*begins to kick himself*

Answer 34

I /believe/ this may be a question that Microsoft use in their interviews (or at least some variation of it)

Answer 35

OMG......I didn't even think of that

Answer 36

Oh, yes I did understand the reasoning, I just didn't see that post when ever I posted mine.

Answer 37

And yes, that is very clever. Haha, I can't believe I didn't see that.

Answer 38

It's a nie little teaser - catches out a lot of people. Surprisingly (or maybe not) - most youngsters get this fairly quickly (under 16 years of age)!

Answer 39

*nice

Answer 40

dont tell me young kids get this quick.....it makes me feel stupid...lol

Answer 41

I feel slightly dunce-ish after that. I feel as though we all should have gotten that. Yay for over-complicating things....
-"if I take the integral of this then...."

Answer 42

he he - not "seeing" something immediately is something we ALL suffer from in life - it doesn't mean that we are stupid - just means that we are human. :D

Answer 43

I tried several things...charts, equations, venn diagrams....AHHHHHHHHHH

Answer 44

maybe that is why most youngsters get it quickly - because they haven't been "corrupted" by equations, charts, etc. :D

Answer 45

so true...lol....I am giving you a medal for this

Answer 46

thx :)

Answer 47

first time I have been medalled for making people feel stupid! :D

Answer 48

These trick questions are awesome :P

How about this one:

On my way to St. Ives I saw a man with 7 wives. Each wife had 7 sacks. Each sack had 7 cats. Each cat had 7 kittens. Kitten, cats, sacks, wives. How many were going to St. Ives?

Answer 49

\[7+7^4\]?

Answer 50

Depends on if he was walking to or from St. Ives.

Answer 51

to

Answer 52

plus 1

Answer 53

\(8+7^4\)

Answer 54

plus 1 again!

Answer 55

\(9+7^4\)

Answer 56

Also depends on whether or not his wives were with him.

Answer 57

on his way he saw those 7 wives and stuff
the question doesn't say that those 7 wives were also heading to st ives.
So the answer is 1. only himself xD

Answer 58

grumble grumble grumble... :D

Answer 59

No where does it say they weren't heading to St. Ives either. And technically speaking, if that's your reasoning, the answer would be 0 since you specified "Kitten, cats, sacks, wives" and not "men"

Answer 60

true :)

Answer 61

Hmm it's from a microsoft interview, and it is true they should have used humans instead of wives :P

Answer 62

are you saying that wives are NOT humans! :D

Answer 63

I'm saying wives are also humans, just as the man

Answer 64

One of my professors this past year accidentally implied that in person. It was funny in an unfortunate sort of way,

Answer 65

I know @thomaster - I was trying to make a joke from your statement - English is a language that can easily be mis interpreted!