Dear Armen,

 Please consult

https://sites.math.rutgers.edu/~zeilberg/Hist21/mt2S.pdf

for the full solutions.


You got 99 points (out of 120).


Here is what you got wrong:

#2: -6 points: the logic is not quite right, and incomplete

#3b: -5 points

#4: -10 points



 Best wishes,

   Dr. Z.