Solution of problem N3790 probability theory total prob

3790. In the box there are 6 parts belonging to workshop No. 1, 4 details — workshop No. 2 and 5 details — workshop No. 3. The probability that the part will be defective for workshop No. 1 is 0.1, for workshop No. 2 - 0 , 2, and shop number 3 produces 10% of the marriage. At random, the Quality Control Department selects the part to be checked, find the probability that it will be standard.