In a school, the average age of students in a class is 14 years old. Knowing that the class is made up of 24 students and that the average age of the boys is 15 years old, what is the average age of the girls?

Let's assume that there are x girls in the class.

We know the following information:

- The average age of the class is 14 years old.
- The total number of students in the class is 24.
- The average age of the boys is 15 years old.

From these, we can set up the following equations:

1. Total age of the class = Average age of the class * Number of students in the class
$$ 14 * 24 = 336 $$

2. Total age of the boys = Average age of the boys * Number of boys
$$ 15 * (24 - x) $$

3. Total age of the girls = Average age of the girls * Number of girls
$$ ? * x $$ (which is the value we want to find)

Since the total age of the class is the summation of the total age of the boys and the total age of the girls, we can write the equation:

$$ 336 = 15(24 - x) + ? * x $$

Simplifying this equation, we get:

$$ 336 = 360 - 15x + ? * x $$

Simplifying further:

$$ 15x - ? * x = 24 $$

Since we don't have enough information to solve for the average age of the girls, we cannot find an exact answer. We can only determine a relationship between the average ages of the boys and girls.