Final answer:
To model the situation, set up a system of equations using x for solo act minutes and y for ensemble act minutes. The correct equations are 3x + 10y = 69 and 3x + 5y = 99.
Step-by-step explanation:
To model the situation, we can set up a system of equations based on the given information. Let's let x represent the number of minutes each solo act lasts, and y represent the number of minutes each ensemble act lasts.
For the first show, we know that there are 10 solo acts and 3 ensemble acts, and the show lasts 99 minutes. This can be represented by the equation 10x + 3y = 99.
For the second show, the 5 solo performers judged best will give a repeat performance, along with the 3 ensemble acts. The second show lasts 69 minutes. Since there are only 5 solo acts in the second show, the equation becomes 5x + 3y = 69.
Therefore, the correct system of equations to model the situation is option A: 3x + 10y = 69 and 3x + 5y = 99.