Friday, January 9, 2015

368: Number Puzzle




source.

27 comments:

  1. Like Dan is alluding to, I also thought it was subtract the two numbers to get the new number. But then I noted the "error" at the end.

    So then I looked solely at the "13 & 21 -> 7." First thought that popped into my head was add the digits of the two numbers and you get 7. Tried that out from the first set of numbers, and it worked. Checked with the rest (determining that ? = 12) and saw that it all worked out.

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    1. I could not understand please explain once again jason

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  2. WTF! Nice catch, Jason. Sharp little dagger there, Curmudgeon.

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  3. Wish I could take credit for it, but I wanted people to try it before telling that it's one of Nob Yoshigahara's puzzles. There's another rendition of it at http://www.puzzles.com/puzzleplayground/NobsNumberTree/NobsNumberTree.htm

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  4. Shouldn't the solution be 15 ?
    If we arrange the numbers as in 99-72, 45 - 27, and so on one realizes that if this pattern continues the answer is 15...

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  5. the answer is 12, idiots, use your tiny brain, btw im in middle school. im just indian................

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  6. Whether the number 21 is a typographical error? If that number is 20, the answer is 15.

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  7. Whether the number 21 is a typographical error? If that number is 20, the answer is 15.

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  8. The catch is the last number 7 is not a typographical error. Hence, the number 21 must be a typographical error!. Instead of 21, it should be 20. If it is so, the answer is 15!

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  9. There are 2 or may be more different patterns/ ways to solve.One way WWE solve 5he result is 15 but that does not fulfill the condition of 7 in the end.2nd way ,the result is 12 & all the conditions are perfect I cluding 7 in the last

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