Tesla Junior Engineer interview questions

I was required to take a 20 question online exam. Most of the questions weren't too difficult, but some could be very ambiguous. ie. Which shape is more efficient? (square, circle, or I-beam) Efficient at what?? After the exam, I had a 1:1 phone interview with one of the senior engineers, which was short 15min. They then asked me to answer 2 essay questions in writing. The CEO then red my resume and said no... That was it. The whole process was fairly quick 20 days or so...