WorldQuant Quantitative Researcher interview questions

Sent my CV, got test invitation in 2 weeks, took the test, 2 weeks later they told me I failed it (dunno how that happened)

I was first contacted by a head hunter and after discussing my background, I decided to complete the application form. Then after two days, I got a phone interview by a committee of three people. The interview consisted of basic questions about my skill sets and probability-based brain teasers. I think I did pretty well but then I didn't commit myself too much and that might contributed to the result of not getting to the 2nd interview.