5.

The local readers' club has a set of 49 hardback books and a set of 21 paperbacks. Each set can be divided equally among the club members. What is the greatest possible number of club members?

14

21

147

7

The greatest possible number of club members is 7

Solution:

Given that, local readers' club has a set of 49 hardback books and a set of 21 paperbacks

Each set can be divided equally among the club members

To find the greatest possible number of club members, we have to find the greatest common factor of 49 and 21

The greatest number that is a factor of two (or more) other numbers.

When we find all the factors of two or more numbers, and some factors are the same ("common"), then the largest of those common factors is the Greatest Common Factor.

Greatest common factor of 49 and 21:

The factors of 21 are: 1, 3, 7, 21

The factors of 49 are: 1, 7, 49

Then the greatest common factor is 7

Thus, the greatest possible number of club members is 7