A,B,C and D play a game of cards. A says to B “If I give you 8 cards, you will have as many as C has and I shall have 3 less than what C has. Also if I take 6 cards from C, I shall have twice as many as D has”. If B and D together have 50 cards, how many cards have A got? Please provide a quick discussion of how you got your answer.