Are at least 10 percent of the people in Country X who are 65 years old or older employed? (1) In Country X, 11.3 percent of the population is 65 years old or older. (2) In Country X, of the population 65 years old or older, 20 percent of the men and 10 percent of the women are employed. 【答案】B 【思路】假设65岁(含)以上男生数为x,女生数为y,..... 我的问题是 为什麽不能用以下方法: >65 ~ >65 employed a b 求a+b+c>10%? ~employed c d (a) a+c=11.3%, a+b+c>10% 成立 我.想.好.久.阿~~~ 不知道为什麽原解法要这样假设? 谢谢~ --

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