In the following question, select the missing number that continues the pattern in the series: 12, 15, 19, 24, 30, ?

Introduction / Context:
This question is a straightforward number series problem from verbal reasoning. The aim is to identify the missing term by observing how each number in the series changes to produce the next one. Such problems check your comfort with differences between consecutive terms and your ability to spot simple arithmetic patterns quickly in examinations.

Given Data / Assumptions:

• Series given: 12, 15, 19, 24, 30, ?
• Exactly one number is missing at the end of the series.
• The rule is expected to be simple and consistent, usually based on addition or subtraction.

Concept / Approach:
For most basic number series, the first step is to calculate the differences between consecutive terms. If these differences themselves form a simple pattern, such as increasing by 1 or by a fixed amount each time, then we can extend that pattern to find the missing number. This idea of working with first differences is the simplest and most effective strategy here.

Step-by-Step Solution:
Step 1: Find the differences between consecutive terms. 15 - 12 = 3. 19 - 15 = 4. 24 - 19 = 5. 30 - 24 = 6. Step 2: Observe the pattern in the differences: 3, 4, 5, 6. Step 3: The differences are increasing by 1 each time. The next difference in this pattern should therefore be 7. Step 4: Add this next difference to the last known term: 30 + 7 = 37. Step 5: So the missing number in the series is 37.

Verification / Alternative check:
Rewrite the series including the missing term: 12, 15, 19, 24, 30, 37. Now recompute the differences: 3, 4, 5, 6, 7. This clearly shows a simple chain where each difference increases by 1. There are no contradictions or irregular jumps, which confirms that 37 is fully consistent with the intended pattern of the series.

Why Other Options Are Wrong:
Options 38, 39, and 40 would give difference patterns 3, 4, 5, 6, 8 or 3, 4, 5, 6, 9 or 3, 4, 5, 6, 10. In all these cases, the difference sequence suddenly jumps, breaking the smooth progression of plus 1 each time. Since exam series are designed with neat regular rules, any choice that disturbs this pattern cannot be correct.

Common Pitfalls:
Some learners guess based on the approximate size of the next number without checking the exact pattern in the differences. Others look for unnecessary complex rules when a simple pattern is present. Always compute consecutive differences carefully and check if they form an obvious sequence before considering more complicated ideas.

Final Answer:
The missing number that correctly completes the series is 37.