Brook and Joyce wanted to find out which was the most popular traditional game at their school: Wulijini, Buroinjin, Koolchee or Keentan. They did a survey of all the students at the school, and found the following:

• Everyone who liked Wulijini also liked Koolchee.
• Some people liked both Koolchee and Buroinjin.
• No one liked both Buroinjin and Wulijini.
• There were more people who only liked Koolchee than people who only liked Buroinjin.
• All the Keentan fans were also fans of Wulijini.