You can send your solution by e-mail to plus@maths.cam.ac.uk.
For some challenging mathematical puzzles, see the NRICH puzzles from this month or last month.
Want facts and want them fast? Our Maths in a minute series explores key mathematical concepts in just a few words.
The BloodCounts! project is gearing up towards one of the largest-scale applications yet of machine learning in medicine and healthcare.
What do chocolate and mayonnaise have in common? It's maths! Find out how in this podcast featuring engineer Valerie Pinfield.
Is it possible to write unique music with the limited quantity of notes and chords available? We ask musician Oli Freke!
How can maths help to understand the Southern Ocean, a vital component of the Earth's climate system?
Was the mathematical modelling projecting the course of the pandemic too pessimistic, or were the projections justified? Matt Keeling tells our colleagues from SBIDER about the COVID models that fed into public policy.