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Everything posted by ujjagrawal

  1. How this answer is absolutely correct... ??? Your clue 2 says... The four teachers are: Lalita, a teacher who teaches in classroom A2 As per above answer... A2 has Sushma... Are you sure of your puzzle... I think its all messed up...
  2. I like bonanova's approach much better though. My workings
  3. I had got the same answers as you... but would like to see how you had worked it out...
  4. There are two friends, who decide to meet at a place between 5 PM to 6 PM everyday. What are the chances that, on a given day, they will be able to meet. Provided- Case 1: They agreed whoever comes first, will wait for 15 minutes for another friend to arrive. Case 2: One friend wait for 10 minutes and other for 20 minutes for another friend to arrive. And which of the above two cases holds better chances of there meeting ?
  5. Thanks for raising above concerns... I assume, I framed the problem in bit hurry... here are the clarification to your concerns... AIM is to minimize average waiting time... Further assume, it's a residential building... all residents mostly travel between their floor and ground floor, so please ignore other in-between floor travels... Hope this problem make more sense now...
  6. Most of the people, I understand, must not be happy with the logic by which the elevators on their building works. This is an opportunity for you to work on a logic that should be efficient, fair and a practical one. There is a 12 floors building (excluding ground level) with 2 elevators. Can you work out what should be the ideal position for the two elevators (in terms of floor numbers), while they are not in use i.e. idle. Assume equal probability of getting calls from all 12 floors.
  7. Both of you are absolutely correct... Witzar I liked the way with ease you worked it out...
  8. An unfair coin has the property that when flipped four times, it has the same probability of turning up 2 heads and 2 tails (in any order) as 3 heads and 1 tail (in any order). What is the probability of getting a head in any one flip?
  9. There's a merciless emperor who has 500 bottles of very expensive wine in his cellar. An assassin infiltrates the wine cellar to poison the wine. Fortunately the emperor’s guards catch the plotter after she has poisoned only one bottle. Unfortunately, the guards don’t know which one of the bottles is poisoned. The poison exhibits no symptoms until death. Death occurs within ten to twenty hours after consuming even the minutest amount of poison. The emperor decides he will get some of the prisoners in his dungeons to test the wine as he has handful of them about to be executed. What is the smallest number of prisoners that must have to drink from the bottles to be absolutely sure to find the poisoned bottle within 24 hours?
  10. When Davey and Ian playing together: Combined probability of hitting a bull's eye will be - 90% + 10% x 80% = 98% (If Davey fails to hit, when going first) or 80% + 20% x 90% = 98% (If Ian fails to hit, when going first) Clearly, more than 97% probability by Alex, so Alex definitely made a BAD bet.
  11. Good work dude... the same answer I have got but with different working...
  12. You have been given three eggs and your job is to figure out how high an egg can fall from a 120 story building before it breaks. The eggs might break from the first floor, or might even survive a drop from the 120th floor, you have no prior information about it. Except all three eggs are know to be of exactly same strength. What's the most efficient way to drop the eggs i.e. reducing the number of times you need to drop eggs and still able to determine the answer? You are allowed to break all three eggs, as long as you identify the correct floor afterwards. After you've solved the above problem, generalize. Define the "break floor" as the lowest floor in a building from which an egg would break if dropped. given an n story building and a supply of m eggs, find the strategy which minimizes (in the worst case) the number of experimental drops required to determine the break floor.
  13. Fully agreed with Bonanova, this problem is a classical paradox... As suggested, my thoughts on the same.... The situation in this problem is a contradiction. Logic very well explain us, there can't be a surprise test next week as then it won't be a surprise. But, in real world, a surprise is a surprise, if logically deducible that won't be surprise any longer. The way Professor has declared about Surprise quiz was totally contradictory on logical basis, it is like saying ' you will have a surprise quiz, tomorrow (logically not sensible). Being heard about the such a surprise quiz, the students should have taken it seriously ... should have started preparing their subjects... hehehe... There is a similar paradox. I will like to put here for all you to give a thought... Once in a town there was a male barber who, every day, shaves every man who doesn't shave himself, and no one else. Do you think such a Barber could ever exist ?
  14. Thanks for the proofs... Even though I will stick too... they are not "EQUAL" but almost equal ... the difference may be infinitesimally small but it exists...
  15. It's not Aptitude but Attitude that decides one's Altitude...

  16. A Logic Class Professor declares on Friday: "We're going to have a surprise quiz next week, but I'm not telling you what day... if you can figure out what day it will be on, I'll cancel the quiz." The students get together and decide that the quiz can't be on Friday, as if the quiz doesn't happen by Thursday, it'll be obvious the quiz is on Friday. Similarly, the quiz can't be on Thursday, because we know it won't be on Friday, and if the quiz doesn't happen by Wednesday, it'll be obvious it's on Thursday (because it can't be on Friday). Same thing for Wednesday, Tuesday and Monday. So it can't be on ANY day, so there's no quiz next week!" They tell the professor, who smiles and says, "Well, nice to see you're thinking about it." On Tuesday, the professor gives the quiz, totally unexpected! What's the flaw in the students' thinking?
  17. No proper solution... apart from few guesses... Still waiting for anyone to solve this one ?
  18. There is a square ABCD with a Cat at A and a mouse at B. The mouse starts walking towards C, while the Cat walks directly towards the mouse. If the Cat walks n times as fast as the mouse, and catches the mouse at C, what is the value of n? Additionally can you also find what is the equation of the Cat's path?
  19. I understand you have got it right but let me put my version of answer too.
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