Google Data Science University Graduate interview questions

I applied online and heard back from a recruiter couple days later. After filling out a detailed situational based and technical/past project related questions form, I had a short chat with the recruiter to arrange live coding/hangout interview. Interviewer was on time, introduced himself shortly, however, he was distanced, curt in responses, and not very friendly, and felt like he was looking down upon me for no real reason. Questions were unexpected. I got questions about linear programming, np hard problem example, how to write objective function and constraints, and a brain teaser. Each time I tried to ask questions to clarify and understand what kind of assumptions I can make or brain storm about my only “ace chance” of brain teaser, he was kind of rude and interrupted me. I totally expected “applied statistics” questions etc. and worked really hard on “data science questions” instead i get OR questions I am not sure why. Maybe there is a statistics aspect that I have never been aware of. I have a background in OR undergrad like 9 years ago completed, but hardly remember anything, and my grad degree is hardly related to OR. There was no coding question, or anything related to data intuition, analysis etc. I was already nervous as it was first interview after grad school, and I did not really expect these. I was stomped and messed the whole interview after not remembering certain definitions etc. and at the very end, i had what is svm question, which i couldn’t reply further than classification algorithm and supervised learning,as i couldnt manage to be more resilient after having a horrible 40 minutes. Overall, a very hard,demoralizing interview.