Total cans = 12
Cans of diet soda, D= 4
Cans of regular soda, R = 8
Two cans are randomly selected from the 12pack:
a) The probability that both contain diet soda:
[tex]\begin{gathered} P(D_1)\times P(D_2|D_1) \\ =\frac{4}{12}\times\frac{3}{11}=0.09090909\approx0.0909(nearest\text{ 4 decimal places)} \end{gathered}[/tex]Hence, the answer is
[tex]0.0909[/tex]b)The probability that both contain regular soda:
[tex]\begin{gathered} P(R_1)\times P(R_2|R_1) \\ =\frac{8}{12}\times\frac{7}{11}=0.42424242\approx0.4242(nearest\text{ 4 decimal places)} \end{gathered}[/tex]Hence, the answer is
[tex]0.4242[/tex]Therefore, as the probability is more than 0.05. So, it is not unusual.
c) The probability that exactly one is diet and exactly one is regular:
[tex]\begin{gathered} P(D_1)\times P(R_2|D_1)+P(R_1)\times P(D_2|R_1) \\ =\frac{4}{12}\times\frac{8}{11}+\frac{8}{12}\times\frac{4}{11}=0.2424+0.2424=0.4848 \end{gathered}[/tex]Therefore, the answer is
[tex]0.4848[/tex]