Find the next letter in the series: B, E, I, N, ?

Appeared in: NORCET 10 Prelims-2026

Explanation

The series progresses by adding an incrementally larger number to the alphabetical position of the preceding letter.
B is the 2nd letter. E is the 5th (2 + 3). I is the 9th (5 + 4). N is the 14th (9 + 5).
The pattern of addition is +3, +4, +5. The next logical step is to add +6.
Adding 6 to the position of N (14) gives 20.
The 20th letter of the English alphabet is T.

Option A: U is the 21st letter. This would mean adding 7 to the previous position (14 + 7 = 21), which breaks the established pattern of increasing the added number by only one (+3, +4, +5, then +6, not +7).
Option C: S is the 19th letter. This would mean adding 5 to the previous position (14 + 5 = 19). This incorrectly repeats the previous addition (+5) instead of continuing the incremental pattern.
Option D: K is the 11th letter. This letter appears earlier in the alphabet than the last letter of the series (N, which is 14th), indicating a backward step that contradicts the clear forward progression of the series.

Visual 1: Infographic: A chart showing the letters of the alphabet numbered 1 to 26, with arrows connecting B -> E -> I -> N -> T, and labels on the arrows showing '+3', '+4', '+5', '+6' to visually represent the pattern.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Logical Reasoning - Letter Series as background academic context rather than a clinical decision trigger.
This type of question, while not clinical, assesses logical reasoning and pattern recognition skills.
Nurses use pattern recognition daily to identify trends in patient vital signs, symptom progression, or lab results, which is crucial for early detection of complications.
Strong analytical skills are essential for interpreting data and making sound clinical judgments, a core competency tested in nursing entrance and competitive exams.

How to Approach the Question

First, observe the given series of letters: B, E, I, N.
Convert each letter into its corresponding numerical position in the alphabet (A=1, B=2, C=3, etc.). This transforms the series into: 2, 5, 9, 14.
Analyze the sequence of numbers to find the mathematical pattern. Calculate the difference between consecutive numbers: (5-2=3), (9-5=4), (14-9=5).
Identify the rule governing the differences. Here, the difference increases by 1 each time (+3, +4, +5).
Apply the rule to find the next term. The next difference should be +6. Add this to the last number in the series: 14 + 6 = 20.
Convert the resulting number back to a letter. The 20th letter of the alphabet is T.

Concept Tested & Keywords

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Practise the full NORCET 10 Prelims-2026

Attempt every question from this paper in a timed mock, then review the full solution for each one.