Portia rates all her first dates as either “duds” or “dudes.” Her date on Wednesday night was a dud. On the next night, she went on a date with someone else who was also a dud. If the probability of her getting two duds in a row was 425, what is the probability that her next date will be a dude ?
A.15
B.925
C.25
D.35
E.2125
我的答案:
Portia rates all her first dates as either “duds” or “dudes.” Her date on Wednesday night was a dud. On the next night, she went on a date with someone else who was also a dud. If the probability of her getting two duds in a row was fff\(\frac{4}{25}\)/fff, what is the probability that her next date will be a dude ?