[填空题]
125 sports fans were interviewed anh 2jxvtu7r- ax.2az73noa1ya d;kfzsf0n4fagr 2 wc:; asked what types of sport they have been to in the lasrcfs;ak 2zg w0f;:n4ft year from a choice of soccer (S) , rugby (R) or baseball (B) . The following information was obtained.
74 had been to soccer
36 had been to rugby
66 had been to baseball
20 had been to soccer and rugby
27 had been to soccer and baseball
24 had been to rugby and baseball
15 had been to all three types of sport
1. Draw a Venn diagram to show the above information.
2. Find the number of sports fans who, in the last year, had been to
1. baseball only;
2. both rugby and baseball but not by soccer;
3. at least two types of sport;
4. none of the three types of sport.
A sports fan is selected at random from those who were interviewed.
3. Find the probability that the sports fan had been to only one type of sport in the last year.
4. Given that the sports fan had been to only one type of sport in the last year, find the probability that the sports fan had been to rugby. ≈
