You can find the problem set and the solutions of the first three editions of the μ-Games here:

– Problem Set – First Edition

– Problem Set – Second Edition

– Problem Set – Third Edition

– Problem Set – Fourth Edition

– Problem Set – Fifth Edition

– Problem Set – Sixth Edition

– Problem Set – Seventh Edition

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