I had two interviews on one day in the middle of December, both half an hour long and about an hour apart. I arrived in Cambridge that morning, went to the porters' lodge where they directed me to the waiting room where there were student helpers with tea and coffee before I went into my interviews. Both of my interviews had two interviewers and they were both academic with the focus being largely on solving problems relating to A-level science or more difficult.

My first interview was about half an hour long and mainly Chemistry-based. It started off quite simple and then progressed to more difficult A-level subjects and beyond. One question involved me drawing a diagram. The way the interviewers led you through the questions let you infer certain aspects. The interviewers could clearly tell I was nervous and were very understanding. I remember forgetting the correct form of a formula which was embarrassing but I think small slip ups like that are ok.

My second interview was largely maths-based, with the beginning focused mainly on graph sketching. The hardest thing I had to do was to integrate a function. I tried many methods to no avail but made sure I voiced my thoughts out loud so the interviewers could see how I thought. Eventually I got completely stuck and my interviewers led me through step by step, giving me small hints and letting me figure out the rest until I got stuck again. In hindsight I reckon the question would have been a stinker even in a second year uni maths paper so I think the idea was to see how you would react to a very difficult problem.

Making sure I was really on it with the things I'd learnt at A-level already - most of the questions started at an easy A-level difficulty and then increased in difficulty until you couldn't answer them any more. Also I practised problem solving by doing past UK physics olympiad and UK chemistry olympiad past papers - they stretch your knowledge and I think helped me tackle some of the more left-field questions. The book "Why Chemical Reactions Happen" by Keeler and Wothers was helpful for the chemistry side. Both authors lecture in first year and it gives you a good taste of what first year chemistry is like.

Don't beat yourself up about mistakes you made during the interview afterwards! Almost all the people I know at Cambridge made errors in their interviews and went on to get in.