In a sixth-grade class, the ratio of boys to girls is 3:2. How many boys and how many girls could there be in this class? Is there more than one possible answer? Explain.

How do you solve?

There's an infinite number of possible answers because there might be any multiplication of 3 for boys and any multiplication of 2 for girls. So, for example:

There might be 3 boys and 2 girls.

There might be 6 boys and 4 girls.

There might be 9 boys and 6 girls.

There might be 12 boys and 8 girls.

etc ...

In each case the ratio stays the same - 3 : 2.

Of course there probably can't be more than a few dozens of people in one class, but theoretically we can raise the numbers up to infinite.