Answer:
[tex]Probability = \frac{243}{1024}[/tex]
Step-by-step explanation:
Given
[tex]Sum = \{7, 11, 12\}[/tex]
[tex]Rolls = 5[/tex]
Required
Probability of not getting audited
If a pair of dice is rolled, the following are the observations of the sum
[tex]Outcomes = 36[/tex]
[tex]Sum\ of\ 7 = 6[/tex]
[tex]Sum\ of\ 11 = 2[/tex]
[tex]Sum\ of\ 12 = 1[/tex]
So, in a single roll; The probability of getting audited is:
[tex]p= \frac{1 + 2 + 6}{36}[/tex]
[tex]p= \frac{9}{36}[/tex]
[tex]p= \frac{1}{4}[/tex]
The probability of not getting audited in a single roll is:
[tex]q = 1 - p[/tex] --- Complement rule
[tex]q = 1 - \frac{1}{4}[/tex]
Take LCM
[tex]q = \frac{4 - 1}{4}[/tex]
[tex]q = \frac{3}{4}[/tex]
The probability of not getting audited in 5 rolls is:
[tex]Probability = q^5[/tex]
[tex]Probability = (\frac{3}{4})^5[/tex]
[tex]Probability = \frac{3^5}{4^5}[/tex]
[tex]Probability = \frac{243}{1024}[/tex]