In a certain city three car brands, A, B, C have 20%, 30% and 50% of the market share respectively. The probability that a car needs major repairs during its first year after purchase for the three brands is 5%, 10% and 15% respectively.
A. What is the probability that a car in this city needs major repairs during its first year after purchase?
B. If a car in this city needs major repair during its first year of purchase, what is the probability that it is made by manufacturer A?