GRE考试

试题来源：2012年新GRE数学考试模拟练习题（2）
【分析解答题】In an insurance company, each policy has a paper record and an electric record. For those policies having incorrect paper record, 60% also having incorrect electric record; For policies having incorrect electric record, 75% also having incorrect paper record. 3% of all policies have both incorrect paper and incorrect electric records. If we randomly pick out one policy,what’s the probability that the one having both correct paper and correct electric records?
(A) 0.80
(B) 0.94
(C) 0.75
(D) 0.88
(E) 0.92

网考网解析：
设总数为x，设incorrect paper record有y, incorrect electri... 查看试题解析出处>>