Final answer:
There are 10,000 possible outcomes when Trsta selects a marble from each box 100 times.
Step-by-step explanation:
When Trsta selects a marble from each box, she is essentially making two independent choices. The first box has 100 marbles, so there are 100 possibilities for the first selection. Similarly, the second box also has 100 marbles, so there are 100 possibilities for the second selection. To find the total number of possible outcomes, we multiply these two numbers together: 100 * 100 = 10,000.