EPSO offers a collection of sample tests for abstract, numerical and verbal reasoning as well as situational judgement tests for both administrators (AD) and assistants (AST). The tests are available in all official EU languages and will give you a general idea of the format and the difficulty of the tests. EPSO does provide a result of the test but doesn´t provide the solutions to each question.
To view the solutions, create a free account at epsoprep.com and view the video explanations under the "Lessons" tab.
To visit EPSOs official site and take the tests click here: EPSO official Sample tests