请教一道数学题 GWD-15 Q35

wildbean · 发表于 2011-11-25 20:27:26

Q35:
For what percent of those tested for a certain infection was the test accurate; that is, positive for those who had the infection and negative for those who did not have the infection?
(1)Of those who tested positive for the infection,
did not have the infection.(2)Of those tested for the infection, 90 percent tested negative.

A. Statement (1) ALONE is sufficient, but statement (2) alone is not sufficient.
B. Statement (2) ALONE is sufficient, but statement (1) alone is not sufficient.
C. BOTH statements TOGETHER are sufficient, but NEITHER statement ALONE is sufficient.
D. EACH statement ALONE is sufficient.
E. Statements (1) and (2) TOGETHER are NOT sufficient.

Lz表示题目没读懂，请大家指教，感激不尽

avalon9527 · 发表于 2011-11-25 23:17:03

题目是问，在那些做了某个感染测试的人中，多少比例是实验精确的？实验精确是指测出阳性的肯定受感染了，阴性的一定没感染
条件一说在那些测出阳性的人中，实际上有八分之一是没有感染的
条件二说所以受试者中，90%结果为阴
不知是否说的清楚了
补充一下，答案是e。因为没法知道测试为阴但却已感染的比例

wildbean · 发表于 2011-11-27 13:50:12

嗯，明白了，多谢啦

请教一道数学题 GWD-15 Q35

所属分类: GMAT考试

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