单选题 Assume a discrete distribution for the number of possible sunny days in Provo, Utah during the week of April 20 through April 26. For this discrete distribution, p(x)=0 when x cannot occur, or p(x)＞0 if it can. Based on this information, what is the probability of it being surely on 5 days and on 10 days during the week?
5 Days of Sunshine 10 Days of Sunshine
①A. A positive value Infinite
②B. Zero Infinite
③C. A positive value Zero
  • A. ①
  • B. ②
  • C. ③
【正确答案】 C
【答案解析】The probability of it being sunny on 5 days during the week has some positive value, but the probability of having sunshine 10 days within a week of 7 days is zero because this cannot occur.