Few brain-twisting questions on a job interview .

Let me open a new topic about trick questions on a job interview by major corporations like IBM, Intel, Microsoft, AT&T ... Hopefully it will help some of us who are about to get a job interview .

Here was a brain-twisting question I was asked during an interview with a large corporation, 5 years ago.

- Given 5 coins with 4 coins having the same weight and 1 coin heavier than the rest , using a jeweler scale, what is the fastest way to find the heavier coin ?

Some other questions I gathered :

1) Why are manhole cover (nắp cống) round rather than square ?

2) How do they make M&M

The main issue is how the chocolate manufacturer gets a perfectly smooth , layered candy shell on a mass-produced food that NEVER knows a human touch until the bag is opened ?

3) Mike and Tim have $21 between them . Mike has $20 more than Tim. How much does each have ? You can' t use fraction.


Give it some thoughts, I will come back to give the answers . Please feel free to share your interview experience .

well are those questions you were asked in a interview? incredible...
for question number 1, i'd do like this.
Take 1 coin out and then, weigh the other 4 coins. If they're equal, then the one you take out would probably be the heavier. If not, weigh 2 coins in the heavier part and you'll get the heavier one you need. Xin loi vi dien dat hoi lung cung nhe, Brit dang voi. May cau sau chua tra loi duoc vi no... ky cuc wa
I wrote ur name in the sky, but the wind blew it away
I wrote ur name in the sand, but the waves washed it away
So I write ur name in my heart, where noone can take it away and 4ever it will stay...

the second question is rather a matter of fact than a trick, I think. Manhole covers are made that way out of the issue of safety. While they both cover the manhole completely when made either way, square covers only do when they are placed properly. If turned sideway, they can drop into the manhole. Round covers always do no matter how you turn them.
I don't get the third question. the 4th, I give up. Perhaps Tim doesn't have any money @ all

Tiền bất kiến cổ nhân
Hậu bất kiến lai giả
Niệm thiên địa chi du du
Độc sảng nhiên nhi lệ hạ

4th. Mike: $20 50 cents, Tim 50 cents
3rd. I was thinking about using a mold, but that seems to be an overkill

OMG, my little brain cracked thinking about the answers for these questions.
I give up . Look forward to knowing the final answers

I am really impressed with answers from Britney, Longatum and Damark . You guys are pretty smart . Your answers would easily passed the test .
For the question about finding the heavier coin among the 5 coins using a jeweler's scale : 1)Pick out two coins and weight them against two other coins . If they are balanced out then the coin left is the one. If one set of 2 coins is heavier than the other set, then weight those 2 coins to get the heaviest. So, the maximum is two (2) steps . This is the concept of binary sort (Computer Science major)
2) The question about why manhole cover is always round , Longatum's answer is the perfect one . Others acceptable one is that people can roll a circular cover if it needs to be moved a short distance while square cover would require a dolly or two persons, another one is the round cover need not to be rotated to fit the hole .
3)The M&M chocolate candy is the toughest one : the chocolate centers are cast in little molds then they are put in a big rotating drum , like a cement mixer . While jostling in the drum, they are sprayed with a sugary liquid that hardens into white candy shell . Constant movement prevents the candies from congealing into a big slums . They're then squirted with colored sugar liquid . This hardens into the coasting on top.
This question is meant to see whether the candidate can come up with convincing answer and avoid saying something stupid
4) The last one, Damark was absolutely right . Candidates are tempted to answer that Mike has $20 while Tim has $1 but the difference is $19 not $20 . The right answer is $20 and 50 cents vs 50 cents since 50 cents is a whole number . This is to test the candidate's conviction to stand up for something that's right. Not a "yes" man type.
By the way, I never knew the right answers until I read them in Reader's Digest magazine . I did try to ask my interviewer when it was done but he refused to give me those answers. Fun huh ! For your information, candidate also has to take an IQ test with questions testing logic and mentality when working under stress . For professional hires, technical questions are also included . The good part is they can't discriminate about age, gender, race or anything else . Merit/qualification is the sole criteria . There was always aberration though.
Được tdhung sửa chữa / chuyển vào 00:20 ngày 12/05/2003