There are between 200 and 300 alien fingers in a room. Each alien has more than one finger on each hand, each has a different nu

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问题 There are between 200 and 300 alien fingers in a room. Each alien has more than one finger on each hand, each has a different number of fingers on each hand, and all of the aliens have the same total number of fingers. How many aliens are there in the room?

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答案至少2个,最多11个

解析 (根据题目可知,一共有200—300根手指,每个人每只手上的手指数不一样,且每个人的左右手手指数总和相等。用排列组合。最少应该有2个,设为甲、乙。则甲左右手手指:49、52。乙:50、51。49+50+51+52=202。最多有11个人,手指的数目依次为:2、23;3、22;4、21;5、20;6、19;7、18;8、17;9、16;10、15;11、14;12、13;总和为275。所以说:至少有2个外星人,最多有11个。)
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