This chapter consists of questions in which series of numbers or alphabetical letters or combinations of both are given, which are generally called the terms of the series. These terms follow a certain pattern throughout the series. The candidate is required to study the given series. identify the pattern followed in the series and either complete the given series with the most suitable alternative or find the wrong term in the series.

Q1: **1. 1, 6, 15, ?, 45, 66, 91**

**Answer :** Clearly, the given sequence follows the pattern:

+5, +9, +13, +17, +21, +25, ........

Thus, 1+5 = 6

6+9 = 15,....

So, missing term = 15+13 = 28

Hence, the answer is 28.

Q2: A, D, H, M, ?, Z

Answer: A \\((\stackrel{+3}{\longrightarrow} D\stackrel{+4}{\longrightarrow}H \stackrel{+5}{\longrightarrow} M \stackrel{+6}{\longrightarrow}S \stackrel{+7}{\longrightarrow}) \) Z

So,the missing letter S.