Ahigh school janitor has 140 keys on his key chain. of these 140 keys, 100 open classroom doors, 80
open the door to the teachers' lounge, and 60 open classroom doors and the teachers' lounge. using this
information, answer each of the following questions.
let c be the event that a randomly selected key opens a classroom and i be the event that a randomly
selected key opens the teachers' lounge.
what is p(c), the probability that a key opens a classroom?
what is p(t), the probability that a key opens the teachers' lounge?
what is pc and t), the probability that a key opens a classroom and the teachers' lounge?
what is pc or t), the probability that a key opens a classroom or the teachers' lounge?