Basically, you should work on the homework on your own, you may discuss
the homework problems with others under condition that:
a) You are not copying others' solutions.
b) You mention the name of the person you collaborated with.
Homeworks are due at the beginning of the class, if you submit the
homework late you will loose 10% of your grade per each day of delay,
you have a maximum of three days delay after which it will not be
accepted.