单选题 If the odds against an event occurring are twelve to one, what is the probability that it will occur?

A、

A. 0.0769.
B、

B. 0.0833.
C、

C. 0.9167.

【正确答案】 A

【答案解析】If the probability against the event occurring is twelve to one, this means that in thirteen occurrences of the event, it is expected that it will occur once and not occur twelve times. The probability that the event will occur is then: 1/13 =0.0769.