The school of science, engineering and design at a local university regularly purchases a particular type of electrical component. 80% are purchased from company A, and 20% are purchased from company B. 5% of those supplied by company A and 4% of those supplied by company B are known to be defective. The components are identical and thoroughly mixed upon receipt. A component is selected at random. Give answers below as decimals rounded to 3 decimal places.
a) What is the probability that this component was supplied by company A and was defective?
b) Calculate the probability that the component was good.
c) Given that the component was defective, what is the probability that it was supplied by company A?