Which of the following numbers is a prime number: 15, 21, 31, 49
Note
31 is prime because it has no divisors other than 1 and itself; 15, 21, and 49 are composite (they have other factors).
Which of the following numbers is a prime number: 15, 21, 31, 49
31 is prime because it has no divisors other than 1 and itself; 15, 21, and 49 are composite (they have other factors).