7 June 2017

# Math whiz Carlo Verschoor and his passion for puzzles: "I'm not interested in things that aren't logical"

Late last year, Utrecht University PhD candidate in Mathematics Carlo Verschoor (26) solved the extremely difficult AIVD Christmas Puzzle for the second year in a row. With no mistakes. In this interview, Carlo explains where his passion for puzzles comes from and why he had a hard time earning his driver's license.

“Languages, history and geography; I realized that those subjects weren’t my thing in secondary school”, Carlo explains. “I got bad grades, and I was demoted to a lower class. But there, everything went so much better, that I could dive into the subject I enjoyed the most: mathematics. That was totally my thing.”

“After I completed senior general secondary education (HAVO), I enrolled in Business Mathematics at the Leeuwaarden University of Applied Sciences. But I wanted more of a challenge, so after my first year I decided to transfer to the university. Last year, I started my PhD research in Utrecht, studying the characteristics of A-hypergeometric functions.”

### Vague theory exam

“The thing that appeals to me most about mathematics is the logic. I’m not that interested in things that aren’t logical. Take a subject like history, for example. When I was at school, it was difficult for me to memorise certain events, because they weren’t logical. After all, you can’t calculate why something happens at a certain moment in time. I had the same problem earning my driver’s license. I thought that the subject ‘recognising danger’, which makes up 50% of the theory exam, was too vague. I could see some element of truth in every multiple-choice question, so I couldn’t decide which answer to choose. You won’t come across things like that in mathematics too often. In mathematics, there is only one right answer.”

### Secret message

“That’s also what makes the AIVD Christmas Puzzle so fun to do. The images and questions all have a secret message, and you have to find out what it is. But one thing is certain: there is a logic to each question. For example, the last question was simply a ‘question mark’, and you had to figure out what it meant. I realised that if you took the first letters of each question, then the question mark would be the last character, and that would form a new question. And it turned out that I was right. The answer to the new question earned me bonus points, and I am the first person to win the puzzle contest two years in a row.”