The common prime factors of 18 and 30 are 2 and 3.
3
The greatest common factor of 54 and 99 is 9, which is not prime. The greatest common factor of 80 and 114 is 2, which is prime.
The pair of numbers that have a greatest common factor of 2 are any two even numbers. This is because the greatest common factor of two numbers is the largest number that divides both numbers evenly. Since 2 is the only even prime number, any two even numbers will have 2 as a common factor.
Since 1, known as the "multiplicative identity", cannot be counted as a factor, there are many pairs of numbers that do not have common factors, such as 2 and 3, 2 and 5, and 3 and 5. There are many pairs of composite (not prime) numbers without common factors, such as 4 and 9. Also, since prime numbers do not have factors, any pair of primes cannot have a common factor, though a pair in which one number is prime may, e.g. 5 and 10.
24 and 49 are relatively prime. Their only common factor is 1. All the other pairs have more than the number 1 as a common factor.
A prime number
Any pair of prime numbers
3
relatively prime or co-prime.
' 1 ' is their only common factor. They're both prime numbers.
Yes, a pair of numbers can have fewer than two common factors. This only happens when the numbers are co-prime -- that is, when the numbers have only one common factor. In that case, the common factor is always 1.
The greatest common factor of 54 and 99 is 9, which is not prime. The greatest common factor of 80 and 114 is 2, which is prime.
Any pair of prime or relatively prime numbers.
Numbers that are relatively prime, like 5 and 7 or 5 and 8.
The pair of numbers that have a greatest common factor of 2 are any two even numbers. This is because the greatest common factor of two numbers is the largest number that divides both numbers evenly. Since 2 is the only even prime number, any two even numbers will have 2 as a common factor.
Prime numbers have one factor pair.
56 and 105