There are not such a question for an interview.
You can find many question from google search.
but honestly saying, its totally depend on interviewer.
I suggest please read about these areas, these will be very helpful for you.
1. Pricing Procedure (I am giving you the document Pricing procedure Details and Steps in SAP MM)
2. Release strategy Setting up Purchase Order Release Strategy
3. Split valuation Split Valuation Activation & its Material Master creation
4. Automatic Account Determination with movement type Automatic Account Determination
5. Procure to Pay Process.
Just read the document, It will be very helpful to you.
If you are expert about these areas, then I am sure you will impress the interviewer.