D is the 4th letter of the alphabet. G the 7th and J the 10th. So which letter comes 13th in the ABC's? 1A 2B 3C 4D 5E 6F 7G 8H 9I 10J 11K 12L <u>13M.</u><u /> This also happens to be the middle of the letters. The numbers are increasing by 3 each time.
