Hey everyone!

To do better at Codeforces contests, a great way is to improve your Math skills!

Wanted to suggest this Counting and Probability Problemset — it has five problems each in 14 different topics:

• Counting
• Venn Diagrams
• Casework
• Complementary Counting
• Handshakes
• Pascal's Triangle
• Combinations
• Paths in a Grid
• Stars and Bars
• States (Markov Chains)
• Generating Functions
• Linearity of Expectation
• Vandermondes
• Burnsides

Each problem either has a solution or a source link (if you click on the source, it will take you to a discussion thread with the solution! Ask here if you are having trouble finding the solution to any question). Those who complete the set of questions will be honored in the Hall of Fame!

You can also check how many times each question has been solved, as well as who has solved each question — in the Summary Tab :)