Answer:
18 students are girls.
12 students are boys.
Explanation:
We can use simple math to solve. First, add 2 and 3 to get the total size per sample group. This will give you 5. Then, divide your total number by your sample group size (30 divided by 5) to get your amount of groups. In this example, there are 6. Then, return to the original ratio of 2:3 and multiply each by your amount of groups. This will give you 12:18. We know that the ratio of boys is 2:3, so there are 12 boys and 18 girls.