5 Each year Jack enters a ballot for a concert ticket. The probability that Jack will win a ticket in any particular year is 0.27 .
- Find the probability that the first time Jack wins a ticket is
(a) on his 8th attempt,
(b) after his 8th attempt. - Write down an expression for the probability that Jack wins a ticket on exactly 2 of his first 8 attempts, and evaluate this expression.
- Find the probability that Jack wins his 3rd ticket on his 9th attempt and his 4th ticket on his 12th attempt.