Question

The athletic club at school sold raffle tickets to raise money for equipment. The club sold a total of 1050 tickets,515 to teachers and 235 tickets to staff. If the winning ticket was picked at random what is the probability of the teacher or other staff member?

Answer 1

Probability of the teacher or other staff is 0.7143

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) =
`(515)/(1050)`

= 103
`(2)/(10)`

= 0.4905

pr(other staff) =
`(235)/(1050)`

= 47
`(2)/(10)`

= 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