Series Completion

Alpha-Numeric Series

In the Alpha-Numeric Series of the IBPS, SBI and other banking exams, sequences that are a combination of the alphabet and numeric series are present. In these questions combinations of letters, numbers, sometimes even symbols are put together as a sequence. You will have to answer questions about the position, sequence rules, coding-decoding etc. These questions have a very high probability of featuring in the IBPS PO, SO, SBI exams and other such exams. Here we will see some of the series questions of this section.

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Alpha-Numeric Series

When you see such a series, the best approach is to assign each “term” a number. In such a sequence, each term could be a symbol, a number or an alphabet. Sometimes there won’t be any order. You will have to answer questions like what is the total number of odd terms? Or what is the sum of the positions of all the symbols etc?  Let us start with those examples.

Alpha-Numeric Series

Example 1: Examine the following alpha-numeric series carefully and answer the questions that follow.

C 1 % E $ H * ( $ 7 $ % 9 @ H L 4 & 2

Q 1: Which of the following is 12th to the right of the 10th from the left?

a) 1          b) $               c) %            d) 4           e) 7

Answer: The trouble will be to keep track. You must mark each position with a number and then if the question asks you to follow a cyclic order, you can easily use addition to do it. For example, let us mark the above alpha-numeric series and make a table of the positions.

C 1 % E $ H * ( $ 7
1 2 3 4 5 6 7 8 9 10
$ % 9 @ H L 4 & 2
11 12 13 14 15 16 17 18 19

Now it is just a matter of tallying the given instructions form the question with the table that we have made. Let us see the instructions present in the question. The first instruction is 10 th from the left i.e. starting from the 19th position, we have to go 10 positions down. In other words, we have to go to the 10th position where we have 7.

Now the second instruction is 12 th to the right of the 10th position. This will land us at position number 2 or the number 1. So the answer a) 1.

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Other Types of Questions

Similarly, you may build many questions with this concept. You would see questions that ask you to reverse the entire sequence or sometimes the half or one-third of the sequence. For example, we have a sequence 1, !, 2, @, 3, #, 4, $, 5, %, 6, ^, 7, &. How many terms are there if every fourth term is counted as two? Well, the sequence has 14 terms, which means there three terms that are the “fourth” terms from the beginning. So the total count will be 17. Remember to put the alpha-numeric series in the form of a table where you shall mark every position if the question is about the position of such particles.

Circular Series & Random Rules

Sometimes the alpha-numeric series will be ordered such that each position is cyclic. By this, we mean that each position can be repeated in a cyclic manner. Also, the examiners could ask literally anything out of the blue. Sometimes questions like how many terms are there or how many terms are numbers etc. Let us see some examples.

Example 2: Observe the following series carefully and answer the questions that follow

A  $ 12 & * E 7 2 1 ! @ I * # @ ! ! O * & # > 8 U >

Q 1: How many numbers follow a vowel alphabet?

A) 1             B) 2           C) 3         D) 4

Answer: The question is not about positioning so there is no need for a table. We will just have to look for the vowel alphabets i.e. a, e, i, o, u. E is followed by 7, and that is the only vowel that is followed by a number. the rest of them have symbols of one or other kind. Thus the correct option here is A) 1.

Q 2: How many vowels will be followed by numbers if the second half of the series is reversed?

A) 1              B) 2                  C) 3              D) 4

Answer: As you can see the only vowel which is preceded by a number is U, so there is only one such vowel and the answer is A) 1.

Q 3: How many symbols are there in the sequence if ! isn’t a symbol anymore?

A) 12               B) 21              C) 13                D) 14

Answer: Anything which is not a number is a symbol here. The count of all such terms is 12. You will have to not include ! and count carefully. Therefore the answer is A) 12.

Practice Questions

In the below space an alpha-numeric series is present. Study the series carefully and answer the questions that follow:

1, !, ), G, 3, *, !, &, B, @, ), 5, &, E, &, ^, I, %, #, O, 7, &, !, $, #, &

Q 1: How many symbols do the alpha-numeric series have?

A) 17                   B) 18               C) 19                   D) 20

Ans: A) 17

Q 2: How many numbers are followed by an alphabet if the second half of the series is reversed?

A) 0                  B) 2                   C) 4                     D) 5

Ans: A) 0

Q 3: Which of the following are related, in some way or the other?

A) G, B              B) B, E             C) E, %               D) G, O

Ans: D) G, O

Q 4: The sum of the numbers that represent the position of all the alphabets is:

A) 65           B) 64                   C) 63                    D) 62

Ans: B) 64

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