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If you add or subtract using only prime numbers is the answer always a prime number?
Wiki User
∙ 13y ago
No, as all prime numbers are odd, excluding 2, and when you add two odd numbers you get an even number. This even number can't be a Prime number as it will be divisible by 2. 101 and 31 are both prime, but 101+31 is 132.
Wiki User
∙ 13y ago
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Does two prime numbers always add up to an even number?
No, they do not. If one of the prime numbers is 2, you will have an odd number.
Could prime numbers can never be even numbers?
Not quite true . . . the number '2' is a prime number. All the rest of the even numbers cannot be prime because they always can be divided by 2.
Is the product of 2 prime numbers always a composite number?
Yes
How can you prove there is no largest prime number?
No. No matter how large of an example you choose, someone always can find a larger number (of any kind), because the upper range of number is infinite. If you take all the known prime numbers and multiply them together, then add 1 to the result, you will have a number that is not divisible by any of the known prime numbers. This number will either be prime or have prime factors that were not previously known. So, in this way, you can always find a new prime number or a number that is a multiple of new prime numbers. If the known prime numbers include all the prime numbers up to the largest known, the new ones must be larger.
Can a even number be a prime number even though all the prime numbers are odd?
Two is even and it's a prime number. All other even numbers can never be prime though because they will always be divisible by 2. So in fact, not all prime numbers are odd, but 2 is the only even prime number.
When is product of 2 prime numbers a prime number?
The product of two prime numbers is always a composite number, and it never is a prime number.
Are odd numbers always a prime number?
No.
Does two prime numbers always add up to an even number?
No, they do not. If one of the prime numbers is 2, you will have an odd number.
Is the sum of any two prime numbers always a composite number?
The sum of any two prime numbers is not always a composite number. The sum of 2 and 11 is 13, and 13 is a prime number, not a composite number.
Is it true that the sum of two prime numbers is always an even number?
Not quite.When two prime numbers of 3 and higher are added together, the result is always even, because all such prime numbers are odd numbers, and when two odd numbers are added together, the result is always an even number.However 2 is a prime number, and 2 is also an even number. Adding 2 (an even number) to a different prime number (an odd number) will always yield an odd number.Only if you don't include "2".
Will a prime number always have an odd numbers of factors?
All prime numbers have only 2 factors which are themselves and one. Al prime numbers are odd numbers except for 2 which is the only even prime number.
Could prime numbers can never be even numbers?
Not quite true . . . the number '2' is a prime number. All the rest of the even numbers cannot be prime because they always can be divided by 2.
Is a prime number always an odd number?
Except for 2 all other prime numbers are odd. Otherwise, they would be divisible by 2 (and thus not a prime number). This does NOT mean that all odd numbers are prime, but that all prime numbers (aside from 2) are odd.
If multiplying 2 prime numbers will the product always be prime?
If you multiply 2 prime numbers. the result will never be prime. A prime number is one that has no factors except itself and one. The number specified in the question has as factors the 2 prime numbers cited.
Why will a prime number times a prime number always equal a composite number?
the two prime numbers will be factors of that number, which would make that number a composite number
Are prime numbers closed under addition?
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..
When you multiply and divide using only prime numbers is the result always a prime number?
No, never.
