Find the angle which is equal to its supplement. ​

At a kentucky friend chicken, a survey showed 2/3 of all people preferred skinless chicken over the regular chicken. if 2,400 people responded to the survey, how many people preferred regular chicken?

Having a hard time understanding this question (see attachment).

Which of the following is an example of a rational number? a. π b. √ 9 c. √ 8 d. 3.8362319