G-Research Quantitative Researcher interview questions

The process began with a 90 minute exam. I can't disclose the details of this. Working my way through the suggested reading material seemed to prepare me quite well for it though. I was informed a few hours afterwards that I had passed, and was invited back for a series of interviews with some of the current quants. These were friendly and challenging. Surprisingly, I was asked nothing about programming or finance. Most of the interviews were structured around stats and probability brainteasers. I received an email the following day letting me know that I wasn't being offered an internship. I sent a polite email thanking them for the opportunity and asking for some feedback from my interviews, but I got no response. I'm disappointed by this, given the amount of time I'd put into preparing for and taking part in the interview process.