In a letter to the editor that appeared in the February 23, 1987, issue of U.S. News and World Report, a reader discussed the issue of space shuttle safety. Each "criticality 1" item must have 99.99% reliability, according to NASA standards, meaning that the probability of failure for such an item is 0.0001. Mission 25, the mission in which the Challenger exploded, had 748 "criticality 1" items. Determine the probability that
a. None of the "criticality 1" items would fail.
b. At least one "criticality 1" item would fail.
c. Interpret your answer in part (b) in words.