Answer:
the correct answer is that mary sold 18 adult tickets and 32 student tickets
if she sold 18 adult tickets it would be 90 dollars, and if she sold 32 student tickets she would get 64 from that, if we add the amount of people that bought tickets and how much she got it would work out
with 18 adults+32 students being exactly 50
and 90+64 being 154.
I tried different solutions, I did 18 adults and 32 Students, since there are 50 tickets sold, this is the correct answer since if we do this the amount she makes from the adults will be 90 and she will make 64 from the students this will add up to $154