c***z
发帖数: 6348 | 1 Two whole numbers, m and n, have been chosen. Both are unequal to 1 and the
sum of them is less than 100. The product, m × n, is given to mathematician
X. The sum, m + n, is given to mathematician Y. Then both mathematicians
have the following conversation:
X: "I have no idea what your sum is, Y."
Y: "That's no news to me, X. I already knew you didn't know that."
X: "Ahah! Now I know what your sum must be, Y!"
Y: "And now I also know what your product is, X!"
The Question: What are the numbers m | c*********g
发帖数: 154 | 2 这样的题目不做也罢，比较不好玩，基本不需要动脑。而且似乎没有实用价值。
就是慢慢筛选掉不可能的组合咯。首先肯定是筛掉除2以外的所有质数，然后再找这样
的和，就是该和的任何一种分解所得到的积都有两种以上的积分解方式。 | p*****k
发帖数: 318 | 3 chaoz, this is known as "the impossible problem". there are
numerous versions, e.g., see:
http://people.sc.fsu.edu/~jburkardt/fun/puzzles/impossible_puzzle.html
personally i really enjoy the story behind about Mr.Gardner's
blooper, with the twist of Sallows's clever interpretation |
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