No.
No. The product of two primes cannot, by definition, be a prime.
By definition, a product of two primes has atwo factors (other than 1 and itself) and so it cannot be prime. So the set is not closed.
Rational numbers are closed under addition, subtraction, multiplication. They are not closed under division, since you can't divide by zero. However, rational numbers excluding the zero are closed under division.
Quite simply, they are closed under addition. No "when".
Yes.
No.
No.
no, not all prime numbers are closed under addition. why? because, when you add 2 prime numbers you will not always get a prime number. example: 5+3= 8 5 and 3 are prime numbers but their sum is 8 which is a composite number..
No. The product of two primes cannot, by definition, be a prime.
No, they are not. You can add two composite numbers, 15 and 14 for example, and get a sum, 29, that is prime.
No.
By definition, a product of two primes has atwo factors (other than 1 and itself) and so it cannot be prime. So the set is not closed.
The set of even numbers is closed under addition, the set of odd numbers is not.
The numbers are not closed under addition because whole numbers, even integers, and natural numbers are closed.
Prime Numbers under 6 are 2,3,5
There are 34 prime numbers under 140.