Group One Trading Equity Derivatives Trader Trainee Co-op interview questions

I became familiar with Group One through a company visit where they gave a lecture on the greeks of derivatives trading. The employees were very enthusiastic about their jobs and seemed to truly enjoy what they were doing, which drove me to apply for their internship via my school's website. First phone interview consisted of several mental math questions of varying difficulty. The second phone interview was over what was on your resume, why you wanted to become a trader, and why you wanted to work for Group One in particular. Both interviewers were friendly and laid back.