Which of the following is a prime number?
- A437
- B161
- C373
- D391
Solution & Step-by-step Explanation
Let's check each option by testing divisibility by prime numbers up to the square root of the number:
For 437:
437
≈20.9. Testing primes 2,3,5,7,11,13,17,19:
437=19×23(Not prime)
For 161:
161
≈12.6. Testing primes 2,3,5,7,11:
161=7×23(Not prime)
For 391:
391
≈19.7. Testing primes 2,3,5,7,11,13,17,19:
391=17×23(Not prime)
For 373:
373
≈19.3. Testing primes 2,3,5,7,11,13,17,19:
Since 373 is not divisible by any of these primes, it is a prime number.
For 437:
437
≈20.9. Testing primes 2,3,5,7,11,13,17,19:
437=19×23(Not prime)
For 161:
161
≈12.6. Testing primes 2,3,5,7,11:
161=7×23(Not prime)
For 391:
391
≈19.7. Testing primes 2,3,5,7,11,13,17,19:
391=17×23(Not prime)
For 373:
373
≈19.3. Testing primes 2,3,5,7,11,13,17,19:
Since 373 is not divisible by any of these primes, it is a prime number.