Cognizant Software Developer interview questions

I am from biotechnology stream so I was basically given a grill interview as to why am I keen on joining an IT firm. I did not give in. I retaliated at every point in a decent polite justifiable manner. I was asked data structures- binary tree printing steps, pattern printing and a few other questions. I was asked to prove that 2+2 equals to 4 which I did(I had practiced the same question..so go through puzzles online) I was asked questions on team leaderships skills as I has mentioned that I am a team leader and a team player keeping in mind my position as the college society's head leader. He was not quite agreeing with my solutions( even though I was write I knew)...so I did answer a little way too firmly and that is when he stopped grilling me on that...it was a 40 minute long interview when others were being down off in 15 minutes.