Azi am fost la un interviu pentru postul de technical support engineer, vacant în cadrul companiei Mind, cu sediul în Tudor Office Center. Am fost supus unor teste, printre care şi unul de logică. Aici am dat de următoarea problemă pe care nu am ştiut să o rezolv.
Two MIT math grads bump into each other at Fairway on the upper west side. They haven’t seen each other in over 20 years.
the first grad says to the second: “how have you been?”
second: “great! i got married and i have three daughters now”
first: “really? how old are they?”
second: “well, the product of their ages is 72, and the sum of their ages is the same as the number on that building over there..”
first: “right, ok.. oh wait.. hmm, i still don’t know”
second: “oh sorry, the oldest one just started to play the piano”
first: “wonderful! my oldest is the same age!”
Problem: how old are the daughters?
Solution
Solution: start with what you know. you know there are 3 daughters whose ages multiply to 72. let’s look at the possibilities…
Ages: Sum of ages:
1 1 72 74
1 2 36 39
1 3 24 28
1 4 18 23
1 6 12 19
1 8 9 18
2 2 18 22
2 3 12 17
2 4 9 15
2 6 6 14
3 3 8 14
3 4 6 13
After looking at the building number the man still can’t figure out what their ages are (we’re assuming since he’s an MIT math grad, he can factor 72 and add up the sums), so the building number must be 14, since that is the only sum that has more than one possibility.
Finally the man discovers that there is an oldest daughter. that rules out the “2 6 6” possibility since the two oldest would be twins. therefore, the daughters ages must be “3 3 8”.
(An astute reader pointed out that it is possible for two siblings to have the same age but not be twins, for instance one is born in january, and the next is conceived right away and delivered in october. next october both siblings will be one year old. if a candidate points this out, extra credit points to him/her.)
This question is pretty neat, although there is certainly a bit of an aha factor to it. the clues are given in such a way that you think you are missing information (the building number), but whats important isn’t the building number, but the fact that the first man thought that it was enough information, but actually wasn’t.
Even if the candidate doesn’t know the solution, they could come up with some interesting thoughts. if they just stare at you and shrug “i dunno” then thank them for their time…
Chiar şi cu soluţia în faţă, pot spune că nu m-aş fi gândit la ea nici într-o sută de ani… şi nu înţeleg de ce este o problemă de logică… 
vineri, 7 octombrie 2011
alecsnokia
Păcat că nu pot fi de faţă la lansare, căci se face în Bucureşti, dar pentru cei care pot ajunge acolo, cică se organizează şi un concurs pentru caştigarea unui dvd cu V8. Mai multe detalii 
