All numbers have factors. Some numbers have some of the same factors as other numbers. These are common factors. If the factor is a prime number, it is a common prime factor. 3 is a prime number. 3 is a factor of 9. 3 is a factor of 12. 3 is a common prime factor of 9 and 12.
30 has three prime numbers and is a factor of 60.
It is 3 that is a common prime factor to both numbers
All of them are prime numbers
1 and 3
Prime number refers to what they are; prime factor refers to what they do. A number doesn't become a factor until it is multiplied. 2 and 3 are prime numbers. 2 and 3 are prime factors of 6.
They are: 3 3 and 5
Any multiple of 3.
27 has one prime factor which is 3 and 3*3*3 = 27
No.
All numbers have factors. Some factors are prime numbers. These are known as prime factors. Some numbers have some of the same prime factors as other numbers. These are known as common prime factors. 3 is a common prime factor of 12 and 15.
2 and 3 are prime numbers that are factors of 12. There is an infinite list of prime numbers that aren't.