The manager of a gas station and convenience store tabulates the following facts:
60% of customers purchase gasoline (G).
38% of customers purchase cigarettes (C).
74% of customers purchase gasoline or a drink (D).
18% of customers purchase gasoline and cigarettes.
21% of customers purchase a gasoline and a drink.
15% of customers purchase cigarettes and a drink.
3% of customers purchase all three items.
(a) If we randomly select a customer, what is the probability that she purchases gasoline or cigarettes? _____
(b) If we randomly select a customer, what is the probability that she purchases a drink? _____
(c) What is , i.e., the probability that a randomly selected customer purchases cigarettes but not a drink? _____
(d) What is the probability that a randomly selected customer purchases exactly one of the three items? _____
(e) Which of the following statements is true?
- G and C are independent.
- G and D are independent.
- C and D are independent.
- None of the three pairs of events are independent.