Sum of two different prime number is a :

Explanation: The sum of two different prime numbers can be either prime or composite. Consider the following cases.

• Case 1: One of the primes is 2. Then the sum is odd and may be prime or composite. Examples: 2 + 3 = 5 (prime), 2 + 7 = 9 (composite).

• Case 2: Both primes are odd (every prime except 2). The sum of two odd numbers is even, and since both primes are at least 3, the sum is an even number greater than 2 and therefore composite. Example: 3 + 7 = 10 (composite).

Conclusion: Because there are cases where the sum is prime and cases where it is composite, the correct answer is that the sum can be either prime or composite.