Very professional interview. First there was an assessment tests that test your basic reasoning abilities, somewhat similar to IQ tests. After that, there was an arithmetic test which consisted of a lot of basic arithmetic questions like 5% of (46 * 32) - 0.37 * 4, without using a calculator of course. Finally there was a sequence test which tested your ability to identify the sequence in a series of numbers. Other than these tests there was a fairly standard interview, asking the usual questions.