Question 6: In a factory for the production of switches there are 4 lines that produce 15%, 25%, 20% and 40%. The percentage of defected switches in the production of these lines are 3%, 2%, 3% and 1% respectively. We draw a switch randomly of the total production of the factory, then: a) What is the probability that the switch is defected? b) If we found that the switch is defected, what is the probability that this switch produced by the second line ?