If 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 haveing both correct paper and correct electric record?
想了半天也不行呀，帮帮忙吧 | 
