Challenge Prompts from Andrew Stewart-Brown provides just what the title says, a video prompt for students trying Maths Challenge questions. Several papers are covered for the Junior (JMC 2014-2019) and Intermediate (IMC 2015-2017) Mathematical Challenges.

Students can select a paper to work on. They should work out the answer on pencil and paper then select their answer, if the answer is correct they can move to the next question. if students give an incorrect response they can watch a video prompt for that question. The video prompt reads the question and provides hints and prompts on how to solve it so students can then try the question again.

This is an excellent resource for students preparing for the Maths Challenges, but of course is also excellent for any student working on their problem solving skills.

From UKMT you can look at full solutions for recent papers also note the investigations and solutions to individual questions for the Junior, Intermediate and Senior competitions. The UKMT Solo Competitions page provides a useful index to resources. Solutions are also available for follow on rounds.

On the outstanding Diagnostic Questions site, you can choose Maths Challenge questions by topic for the Junior, Intermediate and Senior Challenges by choosing the Themed Quizzes option. These quizzes consist of sets of four or five questions grouped by topic. (Log in to Diagnostic Questions to use the link.)

For further challenging problems see the post, Polya – Problem Solving which includes many recommendations.