Aboy bought 9 new cards to add to his card collection of 25 cards. the next day his dog ate half of his collection. how many cards does he have left?

Three numbers x, y, and z are in the ratio 2: 7: 8. if 12 is subtracted from y, then three numbers form a geometric sequence (in the order x, y–12, z). find x, y, and z. there are 2 sets.