An oil company is drilling for oil at three sites. According to the geological tests, the probabilities of determining oil at these three sites are 0.30, 0.15, and 0.20, respectively. The presence of oil at any one of the sites is presumed to be independent of the presence of oil at any of the other sites.
a) What is the probability of finding oil at all three of the sites?
b) What is the probability of not finding oil at any of the sites?
c) What event would be the complement of finding oil at all three sites?
d) What event would be the complement of not finding oil at any of the sites?