For your first problem:
I always think that sometimes the question looks so long and wordy that it puts you off. You should think about simplifying the information mathematically first. Assign a letter to each type of voter. Then think about the information you have and try to link it with some simple formulae.
As a further hint, think about ratios. I don't know how much you know about ratios and their mathematical uses, but they seem to be useful here.
EDIT: hotvette, you posted just as I was writing out my post :)