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Brain Teasers | Tiger and Sheep

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Question:   One hundred tigers and one sheep arc are put on a magic island that only has grass. Tigers can eat grass, but they would rather eat sheep Assume:    A. Each time only one tiger can eat one sheep, and that tiger itself will become a sheep after it cats the sheep.    B. All tigers are smart and perfectly rational and they want to survive. So will the sheep be eaten?      Solution :     Let no of tigers = n     Let's start with 1 tiger(n=1).   Since there is only one tiger it will definitely eat the sheep as there will be no more tigers to eat him once he becomes a sheep.       With n=2 tigers,   If any of the tigers eat the sheep, it will become a sheep itself so the other tiger who is left will definitely eat him. So none of the tigers will eat the sheep.     With n=3 tigers,   The sheep will be eaten since each tiger realizes that once it becomes a sheep there will be two tigers left and none of the two tigers will eat the sheep. So the first tiger to realize this will
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Determine Weight of Counterfeit coins [Asked in GS Interview]

  Question :   There are 5 bags with 100 balls in each bag. A ball can weigh 9 grams, 10 grams or 11 grams. Each bag contains balls of equal weight, but we do not know what type of ball a bag contains. Cookie has a digital scale (the kind that tells the exact weight). How many times does she need to use the scale to determine which type of ball each bag contains?     Solution:   Step 1:   Cookie marks 9 grams ball as  - 1 , 10 grams as  0  and 11 grams as  +1  and bags as Bag1, Bag2.. Bag5       Now let us start with a simple version of this problem:   When no of bags = 1 i.e. we only have Bag1   We need to weigh only one of the balls from Bag1 to determine the type of ball present in   Bag1     When no of bags = 2   If  we pick 1 ball  marked 0  from Bag1  and another ball marked as 0 from Bag2 the sum is 0   Similarly, if Bag1 contains 1 ball marked -1 and Bag2 contains another ball marked as 1 then also sum is 0   So by taking only 1 ball from Bag1 and Bag2 each it will not be possi
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Brain Teasers | Screwy Pirates

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  Question :   Source: Google Five pirates  looted a chest full of  100 gold coin s . Being a bunch of democratic pirates, they agree on the following method to divide the loot: The most senior pirate will propose a distribution of the coins. All pirates. including the most senior pirate, who will then vote. If at least 50% of the pirates (3 pirates in this case) accept the proposal, the gold is divided as proposed. If not, the most senior pirate will be fed to the shark and the process starts over with the next most senior pirate... The process is repeated until a plan is approved. You can assume that all pirates are perfectly rational: they want to stay alive first and to get as much gold as the possible second. Finally, being blood-thirsty pirates, they want to have fewer pirates on the boat if given a choice between otherwise equal outcomes. How will the gold coins be divided in the end?      Solution:     Since the solution for 1 pirate would be trivial let me start with 2 pirates
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