Yen spent 15 of her money on a skirt and 3 shirts. The skirt cost 2 times as much as each shirt. Yen spent 45 of her remaining money on a ring. She spent $364 more on the ring than on the 3 shirts.
(a) What fraction of Yen's money was spent on each shirt?
(b) How much money did Yen have at first?