On this page you will find a collection of nice problems on a broad range of topics, that you can work on as an undergrad or Master's student.
In French:
Cas particuliers du théorème de Fermat-Wiles
Le théorème du point fixe de Brouwer
Le théorème des nombres premiers
Le théorème p^a q^b de Burnside
In English:There will be some at some point...