What will be the next number: 48, 24, 12...?

Appeared in: SGPGI Nursing Officer-2022

Explanation

The series follows a simple pattern of division where each number is half of the previous one.
The first term is 48.
The second term is 24, which is 48 divided by 2.
The third term is 12, which is 24 divided by 2.
To find the next term, the same rule is applied to the last number, 12.
Calculating this gives 12 divided by 2, which equals 6.

Option A: This is incorrect. It does not fit the established pattern of dividing the previous term by 2. Subtracting 3 from 12 gives 9, but the series is based on division, not subtraction.
Option C: This is incorrect. The sequence is decreasing by a ratio, but it will approach zero without ever reaching it in a finite number of steps.
Option D: This is incorrect. This would be the result if the previous term (12) were divided by 3. However, the consistent pattern in the series is division by 2.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Identifying patterns in a number series (Geometric Progression) as background academic context rather than a clinical decision trigger.
While not a direct clinical question, this type of logical reasoning and basic numeracy is a fundamental skill for nurses.
It is essential for tasks like calculating medication dosages, titrating IV drips, and interpreting trends in vital signs or lab values over time.
What if this series represented the halving of a medication dose every 4 hours (e.g., 48mg, 24mg, 12mg)? A miscalculation for the next dose could lead to significant under-dosing, compromising treatment effectiveness and patient safety.

How to Approach the Question

First, analyze the relationship between the first two numbers in the series, 48 and 24. Observe that 24 is half of 48 (48 ÷ 2 = 24).
Next, verify if this same pattern or rule applies to the next pair of numbers, 24 and 12. Confirm that 12 is indeed half of 24 (24 ÷ 2 = 12).
Since a consistent pattern of 'dividing by 2' has been established, apply this rule to the last known number in the series, which is 12.
Perform the calculation: 12 ÷ 2 = 6.
Finally, check the given options to find your calculated result. The number 6 matches one of the options, confirming it as the correct answer.

Concept Tested & Keywords

Concept Tested: Identifying patterns in a number series (Geometric Progression).
Stem keywords: number series, pattern, 48, 24, 12
Lead-in keywords: next number

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