D12 = {e,a,b,b^2 ... b^11, ab, ab^2 ... ab^11}
D12 has 24 elements, with o(a) = 2 and o(b) = 11 and ba = ab^11 [general form being, (b^k)a = ab^-k]

What are all the subgroups of D12, of these which are normal.
Find all factor groups of D12.