Solve this for my confirmation

S1 : I teach algorithms and maths.
S2 : My professor teaches maths,
electronics and computer
science.
S3 : I have a student of maths.
S4 : Algorithm is a part of
computer science.
S5 : Maths students know computer
science.
What would be the chromatic
number of a graph, vertices of which
are the actors/entities that are
involved in the sentences S1 to S5
and edges-to represent the
associations/relationships amongst
the entities/actors as expressed in the
sentences S1 to S5 above ?
(A) 2
(B) 3
(C) 4
(D) None of these

“My Lafter Machin (MLM)
recognizes the following strings :
(i) a
(ii) aba
(iii) abaabaaba
(iv) abaabaabaabaabaabaabaabaaba
Using this as an information, how
would you compare the following
regular expressions ?
(i) (aba)3x
(ii) a.(baa)3x–1. ba
(iii) ab.(aab).3x–1.a
(A) (ii) and (iii) are same, (i) is
different.
(B) (ii) and (iii) are not same.
(C) (i), (ii) and (iii) are different.
(D) (i), (ii) and (iii) are same.

Solve this for my confirmation

“x1 is a clone of x” means x1 is
identical to x in terms of the physical
attributes namely, height, weight and
complexion. Given, height, weight
and complexion only form a
complete set of attributes for an
entity, cloning is an equivalence
relation. What is your impression
about this statement ?
(A) The statement is true
(B) The statement is false
(C) The truth value of the
statement cannot be computed
(D) None of these

NET SOLVED QUESTION PAPERS

Hi,
     I am preparing for NET exam. I have given it two times. But i couldn't crack it. I couldn't crack first two paper also. Third paper is easy for me. Plz tell me how to prepare for First two papers.