题目
The probability that a certain event will occur is x.
The probability that the event will not occur is y.
选项
C.The two quantities are equal.
D.The relationship cannot be determined from the information given.
解析
答案是C。
对于任意一个事件,它要么发生(概率为x),要么不发生(概率为y),不存在其他情况。因此,x + y 的值始终为1。