A car producer stocks three types of tires: a, b, and c. Let p(a) = 0. 40, p(b) = 0. 15 and p(c) = 0. 45. The percentage of defective tires is 2%, 1% and 5%, respectively. Someone picks a tire off the shelf at random and it is brand a. If you want to know the probability that it is a defective tire (event d), which formula would you use?.