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call fire service and save the people

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Call fire service

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The answer is definitely 7, here is a fantastic explanation: http://www.programmerinterview.com/index.php/puzzles/25-horses-3-fastest-5-races-puzzle/ Moins

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It would be 7, mainly because since there only 5 racers each round, then it would be tournament style. As you can tell, tournament style never determines the rankings in the short term. (Imagine if a new tennis player played against Roger Federer and he loses. He's not bad, he's just really unlucky haha) So in order to determine the answer, you would have to use massive logic and reasoning. First step is obvious: you get 5 sets of horses to race through 5 races. So the number is already at 5. We get the top horse in each one and note them. However, one problem is that you have to consider if fastest horses could lie all in the first, second, third, fourth, or fifth group. But we can't determine that yet, so let's race one more time with the winners of each race. Second step: Race with each winner from their groups. That makes 6 total races so far. Ok, now we can get somewhere with this. So now, its a question of which horses we can eliminate to determine the next race. Who can we eliminate though? Well, we can get rid of: - All the horses in the group with the last race that were 4th and 5th place. This makes sense since if the winner of their groups only made 4th and 5th place in the tournament style race, then they are definitely not the fastest horses. 15 horses remaining. - Well, we can also get rid of the last two horses of each group since we are only looking for the top 3. 9 horses remaining. - We also can get rid of the first place winner since we already know he is definitely the best. 8 horses remaining. - Since we already determined who the fastest horse is, now we have to determine who the second and third fastest horse can be. In that case, the second place horse from the last round can get rid of the third horse of that group, since he definitely has no shot of being the first or second fastest horse of this new race. Also, in the third group, we can get rid of the second and third horse in the group due to the same reasoning above. 5 horses remaining. Oh wow! We now have 5 horses left! This means we can just have a clean race and find the second and third fastest horse. So overall, the answer is 7 races! Moins

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It's Disney... CGI effects! The water doesn't really get there, it just looks amazing to the public. Moins

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I would borrow the sorcerer's hat, find all the brooms he left laying around and reanimate them to carry buckets of water up the mountain. It would be magical! Moins

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It doesn't work, please ignore it This one works: public static int smaller(int n){ int i = 1; int result = 0; while(i ＜＝ n / 10 && n / i / 10 % 10＜= n / i % 10) i *= 10; if(i ＞ n / 10) return n; int d = n / i / 10 % 10; int j, x; for(j = 1; (x = n / j % 10) >= d; j *= 10) result = result * 10 + x; result += j * x; result = result * 10 + d; for(j *= 10; j ＜= i; j *= 10) result = result * 10 + n / j % 10; return result + n / i / 100 * i * 100; } Moins

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# Python implementation def getSmallerNumWithSameDigits(num): strNum = list(str(num)) endI = len(strNum)-1 endDigit = strNum[endI] # Walk backwards through digits for i in range(len(strNum) - 1, -1, -1): digit = strNum[i] # If the digit is greater than the end if digit > endDigit: # Swap them strNum[endI], strNum[i] = strNum[i], strNum[endI] break # Put back into int form return int(''.join(strNum)) print getSmallerNumWithSameDigits(912345678) Moins

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These answers are troubling. The only correct answer so far is Ben. The water level goes down. Moins

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The weight of the boat plus you plus the rock has already displaced the height of the water. The only time the water level will change will be when the rock is mid air. Moins

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The answer by Anonymous poster on Sep 28, 2014 gets closest to the answer. However, I think the calculation P[Y] = 1 - P[C1's name != William AND C2's name != William] should result in 1 - (1- e /2) ( 1- e / 2) = e - (e ^ 2 ) / 4, as opposed to poster's answer 1 - (e^2) / 4, which I think overstates the probability of Y. For e.g. let's assume that e (Probability [X is William | X is boy]) is 0.5, meaning half of all boys are named William. e - (e ^ 2) / 4 results in probability of P(Y) = 7/16; Y = C1 is William or C2 is William 1 - (e ^ 2) / 4 results in probability of P(Y) = 15/16, which is way too high; because there is more than one case possible in which we both C1 and C2 are not Williams, for e.g. if both are girls or both are boys but not named William etc) So in that case the final answer becomes: (3e/2 - (e^2)/2) * 0.5 / (e - (e ^ 2) / 4) = 3e - e^2 / 4e - e^2 = (3 - e) / (4 - e) One reason why I thought this might be incorrect was that setting e = 0, does not result in P(C2 = Boy | Y) as 0 like Anyoymous's poster does. However I think e = 0 is violates the question's assumptions. If e = 0, it means no boy is named William but question also says that William is a Boy's name. So that means there can be no person in the world named William, but then how did question come up with a person named William! Moins

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I think second child refers the other child (the one not on the phone) In this case answer to first is 1/3 and second is (1-p)/(2-p) where p is total probability of the name William. For sanity check if all boys are named William the answers coincide. Moins

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Just try to relate safety measures/hazards/etc to previous work experience. There was a relay on a circuit diagram. Just know what it is and basic functionality. Moins

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thank you mate, how about the KVL and KCL? what sort of questions were you asked about in regard? Moins

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I am surprised that not a single person here had noticed that the guy asked to raise a DOUBLE to a given power. Men, double are not integers. Their exponent is stored in a part of their binary representation. If you multiply n times a double you will make n times a rounding error and n useless calculations. Just changed the binary part of the double that is related to its exponent, and here it is, your double has been raised to a given power, a you absolutely lost no precision, and you've made 0 calculations. This is basic stuff, every university teaches that to its students... floating numbers representation... Moins

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TD's answer is interesting, but not very useful. If you actually try it you'll find that since the double's base is 2, any changes to the exponent portion approximately multiply (or divide) numbers by a power of two. I say approximately here, since TD forgot to mention that the number itself isn't stored in float point numbers, only the digits after the implied 1. So yes, it's important to know how floating point numbers work, but modifying the exponent portion of a floating point number is a fundamentally incorrect solution. Moins

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What if one or both of a,b is less than zero. ln(x) for x < 0 is not defined. Moins

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Obviously the interviewer would not allow us to use Math functions like exp, log etc. We are supposed to use the Long division method or the Newton Raphson method to find the quotient. Newton Raphson is the fastest but uses operator * (multiplication) though. Moins