1991 AMC 8 第 14 题

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14.

几名学生参加三场赛跑。每场比赛第一名得 55 分,第二名得 33 分,第三名得 11 分。没有并列名次。一个学生在三场比赛中至少要得到多少分,才能保证他的总分高于任何其他学生?

Several students are competing in a series of three races. A student earns 55 points for winning a race, 33 points for finishing second, and 11 point for finishing third. There are no ties. What is the smallest number of points that a student must earn in the three races to be guaranteed of earning more points than any other student?

99

1010

1111

1313

1515

答案:D
知识点:极端原理
难度评级:1090
解答:

总分 1111 并不能保证第一,例如 5+5+15+5+1 可能被另一个学生也得到 1111 分。

但如果一个学生得到 5+5+3=135+5+3 = 13 分,那么剩下的名次使任何其他学生最多得到 3+3+5=113+3+5 = 11 分。因此 1313 分能保证领先。

所以正确答案是 D

A total of 1111 (for example 5+5+15+5+1) does not guarantee first place, since another student could also reach 11.11.

But if one student scores 5+5+3=13,5+5+3 = 13, the remaining places give every other student at most 3+3+5=11.3+3+5 = 11. So 1313 points guarantees the lead.

Thus, the correct answer is D .

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