This happened in college too. Some dumb assumption off people that because I score so high they can just let me do the work that gets them a good grade.
^I used to get that all the time during my undergrad, until I basically starting avoiding the groups in the library, so they can't approach me. This one girl who was a 'friend', used to always ask to 'compare' our work - basically ask me for almost all the methods and answers for every assignment and I would do it. I was used to having to help others with the work during school times too. Until the third year uni when I had the high-stress/depression issues start and decided not to help her so much to the point just giving her my answers, I would only give her some hints if she asked. She was the sort of person who would drain you, with her constant moody attitude and bitchy comments, I barely even liked her any more. So then one time I was heading to the library with a group who had left this assignment for last minute, and her reaction?.... a whiny 'Oh I did all this work well age ago before the deadline and now you're all just going to take my answers'...

She couldn't even handle one time, whilst for the years I had to put up with her 'comparing' answers with me.
I told her, 'no one's asking you to come with us' in my most bitchy tone of voice and walked off.
Well of course she and I are no longer friends for obvious reasons.
She was also the sort of girl that acts as if she's 'baby cutesy' sort of girl, especially in-front of the guys, and then you're the one who appears to be either a jealous or generally bitchy girl when you point out the facts of what she's really like. The horrible things she would say/her bitchy attitude...which she hides from girls too until she's made friends with you and drawn you into her web, then you're a bit stuck because you know people think she's miss innocent cutesy that if you got into an argument over something you're the one who will appear to be the bad person.
Even my then bf didn't believe me about her, until he saw first hand what her character is really like.
She's a poisonous sort of person, especially if you were/are a sort of chirpy type that I used to be more of, it drains you.