Multiple choice Directions: Complete the following series. HKN, QTW, ZCF, ____ ILO KMN BDG HKM Reveal answer Fill a bubble to check yourself A Correct answer Explanation The first group consists of three different letters and the second group is H + 9, K + 9, N + 9 and so on. The last group should be Z + 9; C + 9; F + 9.