Name two numbers that have a greatest common factor of 28?

Answer 1

Since their GCF is 7, they must both be multiples of 7. Since their LCM is 28, they must both be factors of 28. The only numbers that are both factors of 28 and multiples of 7 are 7, 14, and 28. It cannot be 7 and 14, because the LCM of 7 and 14 is 14. It cannot be 14 and 28, because their GCF is 14. Therefore, it must be 7 and 28.

Answer 2

The factors of 7 are:

1, 7

The factors of 28 are:

1, 2, 4, 7, 14, 28

The common factors are:

1, 7

The Greatest Common Factor:

GCF = 7

Answer 3

There are infinitely many possible answers.

Then HCF(28p, 28q) = 28

where p and q are any two coprime numbers - that is numbers with no common factor between them. They need not be primes themselves. For example 4 and 15.

Answer 4

Two numbers that have seven as their greatest common factor are fourteen and twenty-one.

Answer 5

There are four number pairs that have an LCM of 8. None of them have a GCF of 7. We will not be able to find two whole numbers that satisfy those conditions.

Answer 6

7 is a Prime number. Thus, if 7 is also a factor of 28, then the GCF must be 7. If 7 is not a factor of 28, then the GCF must be 1.

7 is a factor of 28, so the GCF is 7.

Answer 7

28 and 56, among others.

Answer 8

28 and 56, among others.

Answer 9

28 and 56, among many others.

Answer 10

56 and 84