The ratio of boys to girls in the checkers club at one school is 2: 3. the number of club members is more than 20 and fewer than 30. how many club members are there?

We can do this by simply checking each multiple of the ratio.
2:3= 6 members
4:6= 10 members
6:9= 15 members
8:12= 20 members; not enough because there's supposedly more than 20.
10:15= 25 members; let's check if any other values would work.
12:18= 30 members; too much.
So, there are 25 members in the checkers club (10 boys and 15 girls).