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Which of this number 341,351 and 187 is a prime number?

Which of this number 341,351 and 187 is a prime number?
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  • A 341
  • B 351
  • C 187
  • D 382
Correct Answer: Option D
Explanation:
To determine which of the numbers 341, 351, and 187 is a prime number, we need to check the primality of each number. A prime number is a natural number greater than 1 that has no positive divisors other than 1 and itself.

1. Check 341:
- Divisibility by 2: 341 is odd, so it's not divisible by 2.
- Divisibility by 3: Sum of digits \(3 + 4 + 1 = 8\) (not divisible by 3).
- Divisibility by 5: 341 does not end in 0 or 5, so it's not divisible by 5.
- Divisibility by 7:
\[
341 \div 7 \approx 48.714 \text{ (not an integer)}
\]
- Divisibility by 11: Alternating sum of digits \(3 - 4 + 1 = 0\) (divisible by 11).
\[
341 \div 11 = 31 \text{ (an integer)}
\]
- Conclusion: 341 is not a prime number because it is divisible by 11.

2. Check 351:
- Divisibility by 2: 351 is odd, so it's not divisible by 2.
- Divisibility by 3: Sum of digits \(3 + 5 + 1 = 9\) (divisible by 3).
\[
351 \div 3 = 117 \text{ (an integer)}
\]
- Conclusion: 351 is not a prime number because it is divisible by 3.

3. Check 187:
- Divisibility by 2: 187 is odd, so it's not divisible by 2.
- Divisibility by 3: Sum of digits \(1 + 8 + 7 = 16\) (not divisible by 3).
- Divisibility by 5: 187 does not end in 0 or 5, so it's not divisible by 5.
- Divisibility by 7:
\[
187 \div 7 = 26.714 \text{ (not an integer)}
\]
- Divisibility by 11: Alternating sum of digits \(1 - 8 + 7 = 0\) (divisible by 11).
\[
187 \div 11 = 17 \text{ (an integer)}
\]
- Conclusion: 187 is not a prime number because it is divisible by 11.

Given the provided options and their checks, none of the numbers 341, 351, and 187 are prime.

D. 382

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