What should come in place of question mark (?) in the given series?

23 32 43 56 ? 88

Appeared in: DSSSB 6 September 2024

Explanation

The core logic of this series is an arithmetic progression of the differences between terms.
The difference between the first two numbers (32 - 23) is 9.
The difference between the next pair (43 - 32) is 11, which is 9 + 2.
The pattern continues with the difference increasing by 2 each time (9, 11, 13, 15, 17).
To find the missing term, you add the next difference in the sequence (15) to the preceding term (56), which results in 71.

Option A: Adding 16 to 56 gives 72. This breaks the pattern of adding consecutive odd numbers (9, 11, 13, 15...).
Option B: Adding 10 to 56 gives 66. This disrupts the established pattern where the added number is increasing.
Option C: Adding 13 to 56 gives 69. This would mean repeating the previous difference, which contradicts the pattern of the difference increasing by 2 at each step.

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, number series problems test logical reasoning and pattern recognition, which are crucial cognitive skills for nurses.
These skills are applied daily in clinical practice for tasks like interpreting trends in vital signs, calculating medication dosages, and identifying subtle changes in a patient's condition over time.
What if the series was 23, 32, 41, 50? The pattern would be a constant addition of 9. The ability to quickly differentiate between a constant pattern and a progressive one is key to accurate problem-solving.

How to Approach the Question

First, write down the series and look at the numbers to get a general sense of the progression (increasing, decreasing, alternating).
Calculate the difference between each consecutive pair of numbers in the series.
Analyze the sequence of differences you just calculated. Look for a recognizable pattern (e.g., a constant number, arithmetic progression, geometric progression, squares, cubes).
In this case, the differences are 9, 11, 13... which is an arithmetic progression with a common difference of 2.
Use the identified pattern to determine the next difference in the sequence (which is 15).
Apply this difference to the last known term (56 + 15) to find the missing number.

Concept Tested & Keywords

Q8whG89JzuMuI409hmOxo

Practise the full DSSSB 6 September 2024

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