In the single letter series S, Q, N, J, which letter should come next to correctly continue the pattern?

Introduction / Context:
This question is a simple single letter series featuring decreasing steps in the alphabet. It tests whether you can recognise a pattern where the size of the backward step increases in a regular way. Such questions are common in basic alphabet test sections and can usually be solved quickly using numeric positions of letters.

Given Data / Assumptions:
- Given series: S, Q, N, J, ? - Only capital English letters are used. - Alphabet positions: A = 1, B = 2, ..., Z = 26. - We assume a uniform pattern for differences between consecutive terms.

Concept / Approach:
We convert each letter into its numeric position and examine the differences between consecutive values. The pattern is likely to involve decreasing letters with an increasing step size. Once we recognise the sequence of differences, we can extend it to find the next numeric position and then map that position back into a letter. Careful attention to both sign and magnitude of the differences is important.

Step-by-Step Solution:
Step 1: Convert letters to positions. S = 19, Q = 17, N = 14, J = 10. Step 2: Compute differences between consecutive terms. From S (19) to Q (17): difference is -2. From Q (17) to N (14): difference is -3. From N (14) to J (10): difference is -4. Step 3: Identify the pattern. The series is decreasing, and the magnitude of the step increases by 1 each time: -2, -3, -4. Step 4: Predict the next difference. span style="display:block;">Following the pattern, the next step should be -5. Step 5: Apply this difference to the last known term. J corresponds to position 10, so 10 - 5 = 5. Position 5 is the letter E.

Verification / Alternative check:
We can rewrite the entire extended sequence numerically as 19, 17, 14, 10, 5. The differences are -2, -3, -4, -5. This confirms that our rule of decreasing letters by an increasing step size holds throughout. The letter E (position 5) fits perfectly as the next term. Any other letter would break the clean pattern of differences, which is unlikely in a composed exam question.

Why Other Options Are Wrong:
A) D has position 4, which would require a difference of -6 from 10, not -5. C) F has position 6, giving a difference of -4, which repeats the previous step instead of increasing it. D) G has position 7, and 10 - 7 = 3, which does not match the pattern at all.

Common Pitfalls:
Some learners miscount the steps between letters or ignore the fact that the step size itself is changing. Others may try to find a more complex pattern when a simple one is present. The safest approach is to work systematically: convert letters to numbers, compute each difference, and look for a clear sequence in those differences. Once you see the gradual change from -2 to -3 to -4, the next step of -5 becomes obvious.

Final Answer:
The letter that correctly continues the series S, Q, N, J, ? is E.