Find the next number in the series: 1, 3, 6, 10, ?

Appeared in: RML MAINS 2025

Explanation

The series follows a pattern where the difference between consecutive numbers increases by 1 each time.
The first term is 1.
The second term is 1 + 2 = 3.
The third term is 3 + 3 = 6.
The fourth term is 6 + 4 = 10.
Therefore, the fifth term is 10 + 5 = 15.

Option A: The number 12 would result from adding 2 to 10, which breaks the pattern of adding incrementally larger integers (i.e., +2, +3, +4, +5).
Option B: The number 14 would result from adding 4 to 10. This would mean the added number repeated (+4), which contradicts the observed pattern of sequential increase.
Option D: The number 16 would result from adding 6 to 10. This skips the number 5 in the sequence of additions, violating the pattern.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Number Series Pattern Recognition as background academic context rather than a clinical decision trigger.
While not a clinical question, logical reasoning is a critical skill for nurses.
It helps in prioritizing tasks, interpreting patient data trends, and making sound clinical judgments under pressure.
For example, recognizing a deteriorating pattern in a patient's vital signs requires similar pattern-recognition skills.

How to Approach the Question

First, analyze the relationship between the first two numbers. The difference between 1 and 3 is 2.
Next, check the difference between the next pair of numbers. The difference between 3 and 6 is 3.
Continue this process for the entire given series. The difference between 6 and 10 is 4.
Identify the pattern in the differences themselves. The differences are 2, 3, 4, ... which is a simple sequence of consecutive integers.
Apply this pattern to find the next number. The next difference should be 5. Add this to the last number in the series: 10 + 5 = 15.
Select the option that matches your result.

Concept Tested & Keywords

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Practise the full RML MAINS 2025

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