Understanding the Alphabet Series

The question asks us to work with the standard English alphabet series, which runs from A to Z in a forward direction. There are 26 letters in this series.

We need to find the position of a specific letter by following a sequence of directions starting from the right end of the alphabet.

Step-by-Step Solution

Let's break down the problem into smaller steps to find the required letter.

Step 1: Identify the Right End of the Alphabet Series

In the forward alphabet series (A, B, C, ..., X, Y, Z), the right end is the letter Z.

Step 2: Find the Twelfth Letter from the Right

We need to count 12 letters backward from Z. The letters from the right end are:

1. Z (1st from right)
2. Y (2nd from right)
3. X (3rd from right)
4. W (4th from right)
5. V (5th from right)
6. U (6th from right)
7. T (7th from right)
8. S (8th from right)
9. R (9th from right)
10. Q (10th from right)
11. P (11th from right)
12. O (12th from right)

So, the twelfth letter from the right is O.

Step 3: Find the Letter Fourth to the Right of 'O'

Now we are at the letter O. We need to find the letter that is four positions to the right of O in the alphabet series. Moving to the right means moving towards Z.

Starting from O, let's move 4 positions to the right:

1. P (1st to the right of O)
2. Q (2nd to the right of O)
3. R (3rd to the right of O)
4. S (4th to the right of O)

Therefore, the letter fourth to the right of O is S.

Alternative Approach: Using Positions from the Left

We can also solve this by converting positions from the right to positions from the left. The total number of letters is 26.

• Position from the left = (Total letters) - (Position from the right) + 1

First, find the position of the twelfth letter from the right:

Position from the left of the 12th letter from the right $= 26 - 12 + 1 = 15$.

The 15th letter from the left is O.

Next, find the letter fourth to the right of the 15th letter (O). Moving to the right increases the position number from the left.

Final position from the left $= (\text{Position of O}) + (\text{Move to the right})$

Final position from the left $= 15 + 4 = 19$.

The 19th letter from the left is S.

Alphabet Series and Positions

Here is a table showing the letters and their positions from the left and right ends:

From the table, we can verify:

• The 12th letter from the right (Pos Right 12) is O.
• Moving 4 positions to the right from O (Pos Left 15) means moving to Pos Left $15+4=19$.
• The letter at Pos Left 19 is S.

Both methods confirm that the letter is S.

Conclusion

Following the steps, the twelfth letter from the right in the alphabet series is O. The letter fourth to the right of O is S.

Revision Table: Alphabet Reasoning

Additional Information: Positional Logic

Questions involving letter positions in the alphabet series are common in reasoning and verbal ability tests. Understanding how to navigate positions from both the left (starting from A) and the right (starting from Z) is crucial. Remember that moving right from a letter increases its position number when counted from the left, and moving left decreases it. When dealing with positions from the right, it's often helpful to convert them to positions from the left to perform calculations easily.

The formula $Pos_{Left} = Total - Pos_{Right} + 1$ is very useful for converting between left and right positions in any series of a fixed length, not just the alphabet.