An international college buys printers from three different companies F, G, and H. The college buys 50% of the total number of printers from company F, 40% from company G, and 10% from company H. The percentages of defective printers supplied by companies F, G, and H, respectively, are 5%, 3%, and 2%.

a) If a printer is selected at random from the college, what is the probability that the printer is defective?

b) If a printer is found defective, what is the probability that it is supplied by company H?