A middle school principal has 808080 keys on her key chain to distribute to staff on the first day of school. Of these 808080 keys, 606060 open classroom doors, 404040 open the door to the teachers' lounge, and 303030 open classroom doors and the teachers' lounge. Using this information, answer each of the following questions. Let CCC be the event that a randomly selected key opens a classroom and TTT be the event that a randomly selected key opens the teachers' lounge.