Answer:
[tex]\frac{2}{n+2}[/tex]
Step-by-step explanation:
Given
Let the total probability be 1
Probability that Brian wins a raffle = n/n+2
Probability that Brian does not win a raffle = 1 - Probability that Brian wins a raffle
Probability that Brian does not win a raffle = 1 - (n/n+2)
Probability that Brian does not win a raffle = [tex]\frac{n+2-n}{n+2}[/tex]
Probability that Brian does not win a raffle = [tex]\frac{2}{n+2}[/tex]
Hence required fraction is [tex]\frac{2}{n+2}[/tex]