问题
单项选择题
A very large company has twice as many male employees relative to female employees. If a random sample of four employees is selected, what is the probability that all four employees selected are female（）
A. 0.0625
B. 0.0123
C. 0.3333
答案
参考答案：B
解析：
Since there are twice as many male employees to female employees, p (male)=2/3 and p (female)=1/3. Therefore, the probability of 4 "successes"=0.3334=0.0123.