General behavioral questions: Tell me about yourself? Why do you choose consultancy? Why Oliver Wyman? Oliver Wyman specializes in financial services, so be prepared to answer something related to financial area. For the case analysis, your answer needs to be structured and logic, make reasonable assumption. Hypothesis driven analysis technique is useful when structuring your answer, say you first assume the revenue of a company is declining because of decreasing sales volume, you need to verify that in your subsequent analysis, for instance, by asking for sales report of past month etc.