单选题 Given the following table about employees of a company based on whether they are smokers or nonsmokers and whether or not they suffer from any allergies, what is the probability of being either a nonsmoker or not suffering from allergies?

【正确答案】 B

【答案解析】The probability of being a nonsmoker is 240/300=0.80. The probability of not suffering from allergies is 210/300=0.70. The probability of being a nonsmoker and not suffering from allergies is 185/300=0.62. Since the question asks for the probability of being either a nonsmoker or not suffering from allergies we have to take the probability of being a nonsmoker plus the probability of not suffering from allergies and subtract the probability of being both: 0.80+0.70-0.62=0.88. Alternatively: 1-P(Smoker ＆ Allergies)=1-(35/300)=88.3%.