According to news reports in early 1995, among the first Pentium chips Intel made, some had a peculiar defect, which rendered some rarely carried-out arithmetic operations incorrect. Any chip could therefore be classified into one of three categories: Good, Broken (useless), or Defective (operable except for the peculiar defect described above). Suppose that 70% of the chips made were good, 25% had a peculiar defect, and 5% were broken. If a random sample of 20 chips was selected, what is the probability that 15 were good, 3 defective, and 2 broken?