Message Board
Crosswords and other puzzles
For discussion of all forms of mental gymnastics, especially that baffling final clue
| Message board > Crosswords and other puzzles | 96 to 100 of 153 |
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| by jpd - Wed 19th Oct 2005, 9:49pm | ||
Richard said: You could also start on any circle which is Is the right answer.1 + 1 / (2n*pi) miles north of the South pole. The following multiplication contains all the digits 1-9. Fill in the blanks: *** 3* x ---- **** | ||
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| by Richard - Wed 19th Oct 2005, 8:23pm | ||
jpd said: Is the right answer. You could also start on any circle which isIf we assume the small area around the South pole is flat, our start point would be any point on the circle which is 1 + 1 / (2 * pi) miles North of the South pole. Where else could I be? 1 + 1 / (2n*pi) miles north of the South pole. | ||
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| by Richard - Wed 19th Oct 2005, 7:48pm | ||
jpd said: Is that inclusive or exclusive? If it doesn't include 1, then I think 4&13 work.Peter is told the product, 52 Simon is told the sum, 17 52's factors are; 2&26, 4&13 Simon knows that Peter couldn't tell what the numbers were just from the product. If Simon was told 28, then one of the possibilities for 28 are 5&23, but the product of 5&23 is 115 (which can be made in no other way) - so if Simon was told 28, then he couldn't know that Peter couldn't tell what the numbers were. Therefore Simon was told the sum 17. Peter now knows what the numbers are. The possiblities for a sum of 17 are 2&15 (product 30), 3&14 (42), 4&13 (52), 5&12 (60), 6&11(66), 7&10(70), 8&9(72) product 30 gives 2&15(sum 17), 3&10(13), 5&6(11) Only a sum of 13 would be eliminated by Peter when told that Simon already knew that Peter couldn't tell what the numbers were (13 can also be 2&11 whose product 22 can only be formed in 1 way), leaving 2 remaining possibilities therefore Peter can't have worked out the right answer. Therefore it's not 2&15 as the answer. The same argument can be used for 42,60,66,70 and 72, but not for 52. Therefore Simon will also be able to work out that the numbers must be 4&13 | ||
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| by mjb - Wed 19th Oct 2005, 4:22pm | ||
jpd said: how can you possibly walk at the centre of the Earth? You obviously haven't read much Jules Verne then. | ||
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| by jpd - Wed 19th Oct 2005, 4:11pm | ||
Ingers said: I think of 2 integers between 1 and 100. Is that inclusive or exclusive? | ||
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