1. A multiple-choice quiz has 15 questions, each with 4 possible answers of which only one is the correct answer. What is the probability that sheer guess work yields from 5 to 10 correct answers?

2. A manufacturer uses electrical fuses in an electronic system. The fuses are purchased in large lots and tested sequentially until the first defective is observed. If the lot contains 10% defective fuses, find the probability that 5 fuses are tested before a defective fuse is observed.