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