A public library carries 50 magazines, each of which focuses on either news or sports. Thirty of the magazines focus on news and the remaining 20 focus on sports. Among the 30 news magazines, 20 include international news and 10 include national, state, or local news only. Among the 20 sports magazines, 5 focus on international sports, and the remaining 15 focus on national, state, or local sports.
a. Create a table illustrating these numbers, with type of magazine (news, sports) as the row variable.
b. A customer randomly picks a magazine from the shelf and notices that it is a news magazine. Given that it is a news magazine, what is the probability that it includes international news?
c. What proportion of the magazines include international news or international sports?