Answer:
Probability of the teacher or other staff is 0.7143
Step-by-step explanation:
pr(teacher or other staff) = pr(teacher) + pr(other staff) - pr(teacher and other staff)
Total number of tickets = 1050
Number of tickets sold to teachers = 515
Number of tickets sold to other staff = 235
pr(teacher) =
= 103
= 0.4905
pr(other staff) =
= 47
= 0.2238
Since the picking of the wining ticket is mutually exclusive, then;
pr(teacher and other staff) = 0
Thus,
pr(teacher or other staff) = 0.4905 + 0.2238 - 0
= 0.7143