Out of the 30% rejected, (30%)(60%) = 0.18 undergo reprocessing, while (30%)(1 - 60%) = 0.12 go into scrap. Therefore the probability that 1 marble is scrapped is 0.12. Using the binomial theorem for 3 out of 15:
P = (15C3)(0.12)^3 (1 - 0.12)^12 = 0.1696 ~ 0.17, which is choice A.