Identify the next number in the following series: 3, 6, 5, 10, 9, 18, 17, 34, ...?

Appeared in: KGMU 2023

Explanation

The series follows a clear, alternating mathematical pattern.
The pattern consists of two repeating operations: first, multiply a number by 2, and then subtract 1 from the result.
The last given number is 34, which was obtained by multiplying the previous number (17) by 2.
According to the pattern, the next step is to subtract 1 from 34.
Calculation: 34 - 1 = 33. This is the next number in the sequence.

Option A: 34 is the last number currently present in the series, not the next number that follows the pattern.
Option C: 35 would be the result of adding 1 to 34 (34 + 1). The established pattern requires subtracting 1, not adding 1.
Option D: 38 does not fit the established alternating pattern of 'multiply by 2, then subtract 1'. There is no simple arithmetic step from 34 that results in 38 within this pattern.

Visual 1: Flowchart. A flowchart can visually represent the alternating pattern: [Number] -> (Multiply by 2) -> [Result] -> (Subtract 1) -> [Next Number]. This helps to clearly illustrate the two-step process that repeats throughout the series.

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, the analytical and pattern-recognition skills tested are crucial for nurses.
Nurses use pattern recognition daily to interpret trends in vital signs, notice subtle changes in a patient's condition, and identify potential adverse drug reactions.
Strong logical reasoning helps in prioritizing care, making sound clinical judgments, and troubleshooting equipment.

How to Approach the Question

First, examine the relationship between the first few numbers to identify a potential pattern. Notice the change from 3 to 6 (multiplied by 2) and then from 6 to 5 (subtracted 1).
Formulate a hypothesis for the pattern. The hypothesis is an alternating sequence of operations: 'multiply by 2', then 'subtract 1'.
Test this hypothesis against the rest of the numbers in the series to confirm its validity.
5 × 2 = 10 (Matches)
10 - 1 = 9 (Matches)
9 × 2 = 18 (Matches)

Concept Tested & Keywords

Qiro72DL16bVgLjHQ8Z0Y3

Practise the full KGMU 2023

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