1、In an insurance company, each policy has a paper record or an electric record, or both of them. 60 percent of the policies having incorrect paper record have incorrect electric record and 75 percent of the policies having incorrect electric record have incorrect paper record. 3 percent of all the policies have both incorrect paper and incorrect electric records. If we randomly pick out one policy, what is the probability that it is one having both correct paper and correct electric record?
what is the probability that a policy isn't recorded incorrectly? (~P & ~E)
what is the probability that it is one having correct paper [or] correct electric record, [or both]? (P | E)
As for the question "what is the probability that it is one having both correct paper and correct electric record?" (P & E), agree with 耳朵gg that the problem doesn't offer enough information to solve it. However, if the problem states that each policy has a paper record and an electric record, the question is solvable... a revised #1:
In an insurance company, each policy has a paper record and an electric record. 60 percent of the policies having incorrect paper record have incorrect electric record and 75 percent of the policies having incorrect electric record have incorrect paper record. 3 percent of all the policies have both incorrect paper and incorrect electric records. If we randomly pick out one policy, what is the probability that it is one having both correct paper and correct electric record?