Applied online with CV. I was contacted a few days later and had a brief chat on the phone with a lady who then booked me in for interview a couple of weeks later. Arrived at the interview, they gave me money back for my train journey which was generous. Waited 30 minutes for the interviewers to come and get me and they took me to a room. They asked the marble question, but despite getting the question right, they continued to interrupt me and ask why and how I got to the answer. I continued to explain but they didn't seem to want to listen. Interview finished shortly after and was told i'd hear from them in a week, sure enough got the customary brief email to say I wasn't successful. Really strange vibe about the whole place - not sure i'd have taken the job even if offered based on my experience and the feedback read on here prior to the interview.