Solution of problem N3767 probability theory total prob

3767. Products from three workshops came to the finished product warehouse, including: 30% from the first workshop, 45% from the second workshop and 25% from the third workshop. Among the products of the first workshop, the defect is 0.6%, in the second workshop - 0.4% and in the third workshop - 0.16%. What is the probability that a single item taken at random for inspection will end up with a marriage?