peter linz ex. (regular languages)

Question

Answer 1

(a) Regular we need to exclude only those strings when n+l+k =< 5

(b) not regular, L={$a^{6}a^{*} b^{4}b^{*}a^{*}$ | now there is comparison between b's and a's}
which makes this language to DCFL.

(c) L = {$a^{n}b^{l} | \frac{n}{l} $ is integer}  this is CSL not even CFL, because FA and PDA
can't do arithmetic operations.

(d) I think this language is also CSL not even CFL

(e) this is CFL but not regular
     CFG for this language will be:
    S->aSbB / epsilon
    B->b/epsilon

(f) Regular, L = {$a^{100}a^{*}(b+eps)^{100}$}

(g) Not Regular, but it is CFL