Question

Is there an answer sheet for all of the given assignments?

Answer 1

There is an answer sheet in the lecture page in which the assignment is due. Eg, PS 1 was due in Lect 4 so if you look at lecture 4 page at the bottom there is a pdf and a zip file
http://ocw.mit.edu/courses/electrical-engineering-and-computer-science/6-00sc-introduction-to-computer-science-and-programming-spring-2011/unit-1/lecture-4-machine-interpretation-of-a-program/