You can find the problem set and the solutions of the μ-Games here:
– Problem Set – Edition 1
– Problem Set – Edition 2
– Problem Set – Edition 3
– Problem Set – Edition 4
– Problem Set – Edition 5
– Problem Set – Edition 6
– Problem Set – Edition 7
– Problem Set – Edition 8
– Problem Set – Edition 9
– Problem Set – Edition 10
– Problem Set – Edition 11
– Problem Set – Edition 12
Do you like to practise more? Take a look a Project Euler. For example this problem:
Starting in the top left corner of a 2×2 grid, and only being able to move to the right and down, there are exactly 6 routes to the bottom right corner.
How many such routes are there through a n×n grid?
source: https://projecteuler.net/problem=15