Straightforward questions - describe yourself, experience, etc. Had to describe in detail 3 mathematical analysis projects I had been involved with. Then asked a brainteaser question. Follow-up was a problem set that took a few hours to work through.

Phone interview at first and several behavior questions were asked. Then followed by 2 math questions which is pretty hard for an phone interview. Several days later, I received an analytic test, which I did not pass.