Interviewed in 2013 August. Being a PhD candidate, I went through a Problem Solving Test (PST) which comprised of multiple math questions after reading a business case. The test is pretty intense but with enough amount of practice and attention to details, you could pass it easily. After the PST, there was a group interview, where I was put in a room with 5 other candidates. A consultant walked in to give us guidance on "how to do a case" but in actual fact, he asked us case interview questions about exhibits and each of us had to provide insights on the exhibit. It would be unfortunate if you are the last to be asked as there is really limited insights in one exhibit. However, they switch up the answering order for subsequent questions so it is fair for everyone. I was later called that afternoon to be informed that I did extremely well for my PST and I passed that screening round. I was then invited to the first round interview where there were two interviewers. Each started with a behavioral interview and ended with a case interview. It was not super complex and you do not have to know complicated formulas. The calculations may have obscure numbers to work with. It is generally a pressure test and to see if you are "smooth".