Blog posts with problems to get your brain going! You get a new problem every fortnight and the solutions are published later.
If you want the problems delivered to your inbox be sure to subscribe to the Problems newsletter.
The next problem is scheduled for late June.
You may notice some problems are missing... I'm still migrating articles from my old blog.
Can you help these kids trick or treat their entire neighbourhood in this Halloween special?
How can two doctors operate two patients with only two pairs of latex gloves?!
Can you draw 4 triangles in this 5 by 5 grid, covering all dots?