2016 AMC 12B 第 2 题
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所有题目均经美国数学协会（MAA）官方合法授权使用。
2.
两个数的调和平均数可由“它们乘积的两倍除以它们的和”来计算。 与 的调和平均数最接近哪个整数？
The harmonic mean of two numbers can be computed as twice their product divided by their sum. The harmonic mean of and is closest to which integer?
小提示：
乘积的两倍除以和，即 。
Twice the product over the sum:
大提示：
只比一个整数略小；将它四舍五入。
is just a hair under a whole number; round it
解答：
调和平均数为 。因为 非常接近 ，所以这个数略小于 ，最接近的整数是 。
所以正确答案是 A。
The harmonic mean is Since is very close to this is just under so the closest integer is
Thus, the correct answer is A.
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