Large organisations often use aptitude tests, though not all do. They are only used to help with the final decision. Many different types of test exist, so it's worth finding out about what kind(s) may be used, if you can.
Unlike most tests which determine your level of knowledge and abilities, aptitude tests measure ability to learn or acquire knowledge and skills, ie, your potential and capabilities for the future. Typical tests are verbal, numerical and perceptual reasoning.
Aptitude tests cannot be learned, but it is useful to practise to become familiar with them. We recommend you to visit our e-shop and buy a book on the subject.
On the day itself, the administrator will allow you to do a practice test before the actual test to make sure you know what is expected of you.
Even if the tests are impossible to complete within the specified time, complete them as quickly as you can. If you miss a question, go to the next very quickly because your score will depend on the number of correct answers.