Smith industry makes 30,000 yards of fabric per day of which 12,000 are A grade, 9,000 B grade and the rest are C grade fabric. The industry manufactures 84%, 61% and 38% of the raw materials of A, B and C grade fabric respectively and the rest are purchased from a local supplier. a) What is the probability of a fabric being C grade fabric if its raw materials have been internally manufactured? [2 marks] b) What is the probability of a fabric not being B grade if its raw materials have been purchased from a local supplier?