Number and Alphabet series

In each of the following questions, a series of number / alphabet is given which follow certain rules. One of the number / alphabet is missing. Choose the missing number / alphabets from the alternatives given below and mark it on your answer - sheet as directed. 18, 24, 21, 27, ?, 30, 27,

In each of the following questions, a series of number / alphabet is given which follow certain rules. One of the number / alphabet is missing. Choose the missing number / alphabets from the alternatives given below and mark it on your answer - sheet as directed. ELFA, GLHA, ILJA, ? , MLNA

What will come in place of the question mark(?) in the following alphabet series based on their positions in the English alphabet? DGH JMN ?VYZ

Complete the alphabetical series choosing the most appropriate option given below. U,O,ul?,E,A

What will come in place of the question mark(?) in the following alphabet series ? Ac dc ef ig ?

What will come in place of the question mark(?) in the following alphabet series ? KN NL QJ TH ?

What will come in place of the question mark(?) in the following alphabet series ? WE SG PJ LN ?