单选题 Data shows that 75 out of 100 tourists who visit New York City visit the Empire State Building. It rains or snows in New York City one day in five. What is the joint probability that a randomly choosen tourist visits the Empire State Building on a day when it neither rains nor snows?

A. 95 percent.
B. 20 percent.
C. 60 percent.

【正确答案】 C

【答案解析】A joint probability is the probability that two events occur when neither is certain or a given. Joint probability is calculated by multiplying the probability of each event together. (0.75)×(0.80)=0.60 or 60 percent.