Read the following dialogue!
 

Situation: It's the second time for Farel to join the football extracurricular at school. He is talking to Dimas, one of the football team members at break time.

Dimas: How do you feel so far to practice with our team?

Farel: I feel happy. It's very fun to play football with you and the others.

Dimas: Great. I see you go to school by bus. Do you live far from school?

Farel: No, I live near here. It's only four kilometers from school.

Dimas: Where do you live?

Farel: I live at Antariksa Street No. 40, Palembang.

Dimas: Do you live with your parents?

Farel: Yes, and with my elder sister. Do you really like playing football?

Dimas: I do. It's my hobby.

Farel: So do I. I like playing drum too actually.

Dimas: Really?

Farel: I practice playing drum at the music course twice a week. I've joined the course for two years

Dimas: You must be very good at playing drum.

Farel: I think I still need to learn more. I want to be a professional drummer one day.

Dimas: That sounds great. Did you have mathematics test this morning at your class?

Farel: Yes, I did. Did you also have it?

Dimas: Yes. The test was so difficult. In my view, mathematics is the most difficult subject.

Farel: Mathematics is my favorite subject.

Dimas: Why do you like it?

Farel: I like it because it is so challenging.

Answer the question based on the dialogue above.

8. Why does Farel like mathematics?