Formulas to solve alphabet series questions

Alphabet series consists of a series of letters positioned differently following a logical pattern. One has to analyze the pattern the series is following and accordingly find out the missing/wrong alphabet of the series.

For this, we have to memorize the position of each alphabet. This can be done by following some simple concepts mentioned below:

Concepts for decoding the alphabet series:

1.The Alphabet concept:

Since we all know that English alphabets contain 26 letters which are discussed below:


This can be divided into two parts. The first part contains 13 letters beginning from A to M and the second part starts from the 14’Th letter that is from N to Z

Hence the first alphabetical part will be:

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And the Second Alphabetical Part will be :

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2. EJOTY Concept:

By using this concept, we can easily remember the position of different alphabets and accordingly find out any letter without much effort. All we have to do is remember the place of these five letters which is mentioned below:

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Say for example if we are asked to find out the 26’th letter from the left-hand side of the alphabet series, then since we already know the 25’th letter is Y, hence instantly we can make out that the 26’th letter will be Z.

Hence the EJOTY concept helps in memorizing and finding the position of any letter in the alphabetical series.

3. RHS concept:

Sometimes we are being asked to find the position of the letters from the opposite side or right-hand side of the series; this concept simplifies the task of finding out that letter.

This is illustrated in a better way with the help of an example below:

Let’s imagine eight friends A B C D E F G H are standing in a row; now we have to find out the position of E from both the left-hand side and from the right-hand side of the row?

It is better explained with the help of a diagram

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By looking at the above figure it is evident that E is at the 5’th position from the left side of the row, but he is placed at the 4’th position when it comes to finding his location from the right-hand side.

This can be presented with the help of a simple formula:

Let the position of the person (given in the question) be r.

Hence his position from the right-hand side will be = n+1-r

Where n= Total number of people in the series

In this case, it will be

N= 8 r= 5 (position of E from the LHS that is given in the question)

Therefore his position from the RHS = 8+1-5= 4

Hence he will stand at the 4’th position from the RHS.

The same formula can be applied with vertical series as well.

4. Finding the middle digit of the given series:

Here we have to find the middle letter of any sequence that is provided in the question.

For example:

Find the middle letter between the 10’th letter and the 22’nd letter of the left-hand side of the series?

Solution :

This can be quickly found out by adding the positions and getting their average.

In this case, it will be 10+22= 32/2= 16

Hence the 16’th letter will be the center of the given series, and since we all know from the BJOTY series that O is the 15’th item from LHS, hence the 16’th term will be P.

Therefore P comes in the middle of 10’th and 22’nd series.

In case of finding the middle letter from the RHS :

Consider the same above question

Find the middle letter between the 10’th letter and the 22’nd letter of the right-hand side of the series?

10+22/2= 16’th item from the right that is K.

And if we convert it to LHS method, then all we have to do is to deduct the above number from 27= 27-16= 11’th item

And we know that BJOTY concept that the 10’th article is J Hence the 11’th article will be K.

Hence all the above concepts are generally used to solve alphabetical series questions asked in competitive exams.