This type of reasoning is a mixed bag of coding-decoding, series-based reasoning and finding positions based reasoning questions.

**Points to note:**

Before jumping to the questions, let us understand the meaning of few key words that are generally used in such questions like **"following, followed by, preceding, and preceded by"**.

- Let us take two successive alphabets Y and Z. Here, Y is preceding Z and Z is preceded by Y. Also, Z is following Y and Y is followed by Z.
- Now, take three successive alphabets: X, Y and Z. Here X and Y are preceding Z, but Y is immediately preceding Z whereas, X is not immediately preceding Z. Similarly, Y and Z are following X, but Y is immediately following X whereas, Z is not immediately following X.

**Alphanumeric Series: Solved Examples**

**DIRECTIONS (Example no. 1-5):** Study the following digit-letter-symbol sequence carefully and answer the questions given below:

4 P + S r 9 B # A 3 ? 7 c > Z % 6 d & Q @ 1

**Example 1:** If the above sequence is written in the reverse order, then which element will be 5^{th} to the right of 16th element from the right end?

**Solution:** Reversed Sequence - 1 @ Q & d 6 % Z > c 7 ? 3 A # B 9 r S + P 4.

Hence, now the 16^{th} element from the right end is % and 5^{th} to the right of % is ?

*Shortcut method: *There is an alternate way to find the answer without writing the sequence in reverse order.* *Since both the directions are given from right, subtract them: 16R - 5R = 11R

Now, as the questions asks the sequence to be reversed, the element is 11th from **left** of the original series, i.e. '?'.

**Example 2:** How many such numbers are there in the above sequence, each of which is immediately preceded by a consonant and immediately followed by a symbol?

**Solution:** Check for the sequence Consonant-number-symbol. There is only **1 such case** in the above sequence: **A 3 ?**

**Example 3:** Which element is seventh to the left of sixteenth element from the left in the above sequence?

**Solution:** The sixteenth element from the left is %. Now, we move 7^{th} to the left of %, which is A. Hence, **A** is be the answer.

*Shortcut method: *Since both the directions are given from left, we will subtract them: 16L - 7L = 9L

So, the 9th element from left is **A**.

**Example 4:** If the first half of the series is written in reverse order, then which element will be fourteenth from the right end?

**Solution:** There are a total of 22 characters in the above sequence. Since, the first half of the above sequence is reversed, therefore, the sequence is:

? 3 A # B 9 r S + P 4 7 c > Z % 6 d & Q @ 1So, the required 14^{th} character from right is '+'.

*Shortcut method: *There is another way to solve the question without reversing the first half of the series. Since there are a total of 22 characters in the sequence, the first half contains 22/2 = 11 characters.

Subtracting, we get: 14R - 11R = 3R. For the reversed half, it will be 3rd element from the **left** of the original series, i.e. '+'.

**Example 5:** Which element will be fourteenth from the right end, if second half of the series is reversed?

**Solution:** There are total 22 characters given in the above sequence. As only the second half is reversed the sequence becomes:

4 P + S r 9 B # A 3 ? 1 @ Q & d 6 % Z > c 7. So, the required 14th character from right is A.

*Note: *If you see carefully, you can find the answer without reversing the second half. As each half contains 22/2 = 11 characters, the 14th character from right end will be in the first half.

So, it can be directly found from the original series; 14th character from right of the original series is 'A'.

**Alphanumeric Series: Key Learning**

- One of the most scoring question-type in any competitive exam is alphanumeric series puzzles. These questions are high scoring as they can be solved very quickly.
- Learning shortcuts to handle these types of questions will significantly boost your reasoning score. Hence, try to practice as many questions as you can.

**For any query on any concept or example, feel free to post in the comment section below.**