Apple Mechanical Engineer interview questions

Had a phone interview with recruiter. Then had a phone interview with the engineering manager. Was given a project to complete in one week before the face to face interview. The interview consisted of 10 half hour interviews where every interviewer had one challenge question. If you got the challenge questions wrong you don't get an offer.

1 round phone interview and then onsite. Phone interview is easy. During onsite, 9 people interviewed me. Most questions are related with mechanics of material. The rest are behavior questions.