A number formed by adding prime number do not have the same prime as factors.

Example 2 and 3 are prime numbers; 6 or 2 * 3 has prime factors 2 and 3.
But 2+ 3= 5 which doe snot have prime factors as 2 and/or 3.

So u mean to say that whenever factors are talked about, we have to consider multiplication and noting else, but there are other cases too, for example, 3+7=10=2*5 all are prime of 10
I apologise if you get frustated because of my reasoning, but please help me understand this concept. Thanks in advance.

When you perform the prime factorization of a number, for instance, 10, of which the prime numbers are 2 and 5, then you to BACK to the previous number you must do a multiplication.

So, if the question asks you for a number composed of prime numbers > 2 the number as result must be the product of these numbers NOT the addition.

Hope now is clear