Deloitte offers a wide range of products and services, so you will likely run into a situation where you're unsure how to answer a question. The interviewer wants to discover more about how you would react under pressure and when you lack the knowledge necessary to answer a question. Demonstrate to the interviewer that you can acknowledge when you don't know something instead of making it up on the fly and commit to finding that answer and following up with the customer timely. Give an example of how you self-help and track down information or how you've found the appropriate person to ask. Telling a customer, "I don't know," or "that's not my department," is never appropriate, and the interviewer wants to learn more about your customer service skills and problem-solving approach.