Other Math Answers

Which of the following is TRUE?
(A) Every subset of a regular set is regular.
(B) Every finite subset of a non-regular set is regular.
(C) The union of two non-regular sets is not regular.
(D) Infinite union of finite sets is regular.

Consider the languages
L1= {a^n b^n c^m | n,m > 0} and L2= {a^n b^m c^m | n,m > 0}

(A) L1 intersection L2 is a context-free language
(B) L1 union L2 is a context-free language
(C) L1 and L2 are context-free language
(D) L1 intersection L2 is a context sensitive language

What is the language {a^m b^(m+n) | m,n >= 1} ? Explain.

(A) regular
(B) context-free but not regular
(C) context sensitive but not context free
(D) type-0 but not context sensitive

Which of the following are decidable?
1. Whether the intersection of two regular languages is infinite
2. Whether a given context-free language is regular
3. Whether two push-down automata accept the same language
4. Whether a given grammar is context-free
(A) 1 and 2 (B) 1 and 4
(C) 2 and 3 (D) 2 and 4

Which of the following is true for the language{a^P | P is a prime} and why?
(A) It is not accepted by a Turning Machine
(B) It is regular but not context-free
(C) It is context-free but not regular
(D) It is neither regular nor context-free, but accepted by a Turing machine

Which of the following languages is regular?
(A) {WW^R |W belongs to {0,1}^+}
(B) {WW^RX | X,W belongs to {0,1}^+}
(C) {WXW^RX | X,W belongs to {0,1}^+}
(D) {XWW^RX | X,W belongs to {0,1}^+}

The language L = {0^i 21^i | i <= 0} over the alphabet {0,1,2} is
(A) not recursive
(B) is recursive and is a deterministic CFL
(C) us a regular language
(D) is not a deterministic CFI but a CFL

If the entire program is written in FORTRAN, the percentage increase in the execution time, compared to writing the entire program in FORTRAN and rewriting the 1% in assembly language is
a) 0.9
b) 0.8
c) 8
d) 9

To completely write the program in FORTRAN and rewrite the 1% code in assembly language, if the project needs 13 days, the team consists of

a) 13 programmers
b) 10 programmers
c) 8 programmers
d) 100/13 programmers

If the strings of a language L can be effectively enumerated in
lexicographic (i.e. alphabetic) order, which of the following statements
is true?
(A) L is necessarily finite
(B) L is regular but not necessarily finite
(C) L is context free but not necessarily regular
(D) L is recursive but not necessarily context free