Ever since I learned about Project Euler, I have been astonished and wondering about how Colin Hughes (the creator of Project Euler) manages to come up with such problems at such a rapid pace (once a week, except for Summer). The criteria for PE is very clearly and narrowly defined.

  • The problem has to be challenging.
  • The problem has to be impossible to brute force.
  • The problem has to require some mathematical insight.
  • But even with the insight, you need some programming skills.
  • An efficient program can always be written which will solve the problem in under a minute.
  • The problems are recreational and fun.

Note that not all PE problems satisfy all of these criteria strictly. The problems do range in difficulty. Obviously not all problems are "fun" for everyone. An easy problem can be brute forced in a reasonable amount of time, etc.

Being a math educator myself, I also, very frequently, have a defined objective. But I find it very difficult and time consuming to come up with good math problems that satisfy my objective, for my students. Many others have this problem and related questions have been asked on this forum multiple times.

So my question is,

  • How can Project Euler come up with so many good problems with a frequency (that I think is) so high?

I am genuinely curious about this. Is there a big group of researchers/educators which works on this? Is there an army of grad students which does the research and finds the solution before a problem is posted? Or is it simply talent which cannot be taught and passed-on? If it is a skill, I am hoping that it'll help myself and others with the problem of problem-designing.

  • $\begingroup$ it is unclear, are you talking about project euler or project euclid? im assuming euclid, but i wanted to check before editing your post $\endgroup$
    – celeriko
    Commented Mar 3, 2017 at 17:44
  • $\begingroup$ @celeriko I am asking about project Euler. I have fixed it. $\endgroup$ Commented Mar 3, 2017 at 20:16

1 Answer 1


You can read on PE's website that questions are either

  • Classic questions
  • Questions that are derived from some theorem in some way
  • Other questions are believed to be original

There are now over 600 questions and they have admitted in the past that they are starting to run out of questions (since they've already covered a lot). At some point, they started releasing questions every two weeks instead of every week; not sure what the frequency is right now.

They rely on the community to submit question ideas, so you are not too far off in claiming that there is some army of people working on the project.

  • 1
    $\begingroup$ There was also, and presumably still is, a small group of people who test run questions to judge their difficulty and interest. $\endgroup$ Commented Jul 30, 2018 at 7:38

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