ANSWER
[tex]32\text{ tickets}[/tex]EXPLANATION
The group consists of 4 friends and each friend has 12 tickets.
Each friend uses 4 tickets to ride the roller coaster.
To find the number of tickets each friend has after the ride, subtract the number of tickets used for the ride from the number of tickets each friend had initially.
That is:
[tex]\begin{gathered} \Rightarrow12-4 \\ 8 \end{gathered}[/tex]Now, to find the number of tickets the group has, multiply the number of friends in the group by the number of tickets left:
[tex]\begin{gathered} 4\cdot8 \\ 32\text{ tickets} \end{gathered}[/tex]