If the ratio of boys to girls in class is 3:2 and there are 15 boys, how many girls are there?

Correct Answer: A. 10

To find the number of girls in the class, we use the given ratio and the number of boys.
Step 1: Understand the ratio
The ratio of boys to girls is 3:2. This means that for every 3 boys, there are 2 girls.
Step 2: Represent the ratio
Let the number of boys be 3x and the number of girls be 2x, where x is a scaling factor.
Step 3: Substitute the given value
It is given that there are 15 boys. Thus:
3x=15
Step 4: Solve for x
Divide both sides by 3:
x= 15/3 = 5
Step 5: Calculate the number of girls
The number of girls is 2x
2x =2 ×5 =10
Step 6: Match with the options
The correct answer is: A. 10