A manufacturer of computers has three plants, A, B, and C. Plant A manufactures 60% of the computers, plant B manufactures 15%, and plant C manufactures 25%. Plant A has a defective rate of 0.5 per hundred, plant B has a defective rate of 1 per hundred, and plant C has a defective rate of 2 per hundred.
Question:
If a computer is to be selected at random, find the probability that it is defective and if a defective computer is found in a store, fine the probability that it came from Plant B.