Final answer:
The number of ways to select 3 markers when there are more blue markers than red markers is 24.
Step-by-step explanation:
The number of ways to select 3 markers when there are more blue markers than red markers can be calculated using a tree diagram. The first set of branches represents the first draw, with 8 ways to draw a blue marker and 3 ways to draw a red marker. The second set of branches represents the second draw, with 8 ways to draw a blue marker and 3 ways to draw a red marker, regardless of the choice on the first draw. Reading down each branch results in the total number of possible outcomes. Counting the outcomes that consist of a blue marker on the first draw and a red marker on the second draw, there are 24 ways. Therefore, the answer is 24 (option C).