options: Derive the formula for the sum of a finite geometric series (when the common ratio is not 1), and use the formula to solve problems. For example, calculate mortgage payments.

Choose and produce an equivalent form of an expression to reveal and explain properties of the quantity represented by the expression.
problem_activity: The basketball team sold t-shirts for a fundraiser. They sold a total of 23 items and made a profit of $246. They made a profit of $10 for every t-shirt they sold and $12 for every hat they sold.
Determine the number of t-shirts and the number of hats the basketball team sold.


correct_option_index: 1