theory of computation

Question

Answer 1

a)
S -> aSb | aSB | b
B -> bB | epsilon

b)
S-> aSbb | epsilon

c)
S-> aaA
A-> aAb | ab   (n=1 minimum)

d)
S-> aaaA
A-> aAb | epsilon  (n=3 minimum)

Edit is coming soon for the rest. Out of patience .. :D

Answer 2

Please verify 

h) L1 - L4' = { } . So simply S-->S will not produce any string (including epsilon)