Question

Study the given number series and answer the question that follows. 26749365195245942371 How many even numbers are immediately preceded by an odd number and immediately followed by a prime number?

• A. 3
• B. 2
• C. 4
• D. 1

Answer 1

Answer:

B. 2

To find the correct count, let's break down the required condition for the numbers in the series.

We are looking for groups of three numbers that follow this specific pattern:
[Odd Number] $\rightarrow$ [Even Number] $\rightarrow$ [Prime Number]

(Note: The prime numbers available in this series are 2, 3, 5, and 7).

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Let's look at every even number in the series (2, 6, 4, 6, 2, 4, 2) and check its neighbors:

1. 2 6 7... $\rightarrow$ Preceded by nothing. (Invalid)

2. 2 6 7... $\rightarrow$ Preceded by 2 (Even). (Invalid)

3. 2 6 7 4 9... $\rightarrow$ Preceded by 7 (Odd), followed by 9 (Not Prime). (Invalid)

4. ...9 3 6 5... $\rightarrow$ Preceded by 3 (Odd), followed by 5 (Prime). $\rightarrow$ [Match 1: 3-6-5]

5. ...1 9 5 2 4... $\rightarrow$ Preceded by 5 (Odd), followed by 4 (Not Prime). (Invalid)

6. ...5 2 4 5... $\rightarrow$ Preceded by 2 (Even). (Invalid)

7. ...5 9 4 2... $\rightarrow$ Preceded by 9 (Odd), followed by 2 (Prime). $\rightarrow$ [Match 2: 9-4-2]

8. ...9 4 2 3... $\rightarrow$ Preceded by 4 (Even). (Invalid)

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Final Answer

There are exactly 2 even numbers that satisfy the given conditions (the 6 in 3-6-5 and the 4 in 9-4-2).