From the question we have the following information given;
![\begin{gathered} \text{Total racers}=310 \\ \text{Completed}=277 \\ \text{Gave up}=21 \\ \text{Disqualified}=12 \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/high-school/4iismkaazovxj3sio2t9cnlwq9kao6uiin.png)
This means the number of racers that did not complete the marathon was a total of those who gave up and those who were disqualified. That is, 33 racers did not complete the marathon.
Therefore, the percentage that did not complete the marathon would be calculated as follows;
![\begin{gathered} Did\text{ not complete}=(33)/(310)*100 \\ \text{Did not complete}=(3300)/(310) \\ \text{Did not complete}=10.645\% \\ \text{Rounded to the nearest hundredth;} \\ \text{Did not complete}=10.65\% \end{gathered}](https://img.qammunity.org/2023/formulas/mathematics/high-school/v5a0ow8i5ncd27m9cygqyxyn13dgv95gpa.png)
ANSWER:
The percentage that did not complete the marathon was 10.65%