FAG GAF HAI IAH ____
a. The middle letters are static, so concentrate on the ﬁrst and third letters. The series involves an alphabetical order with a reversal of the letters. The ﬁrst letters are in alphabetical order: F, G, H, I, J. The second and fourth segments are reversals of the ﬁrst and third segments. The missing segment begins with a new letter.