问题
单项选择题
The probability of each of three independent events is shown in the table below. What is the probability of A and C occurring, but not B（）
A．15%
B．42%
C．8.9%.
答案
参考答案：C
解析：
Using the multiplication rule : (0.25)(0.42)-(0.25)(0.15)0.42)=0.08925 or 8.9%.