Problem 4. In one class, there are 16 boys and 14 girls. On the math test, the class average is 88 points. If the average score of the boys is 81, what is the average score of the girls?
Solution. Let's denote the average score of the girls with $x$. Then, the girls scored $14 x$ points, and the boys scored 16.81 points. However, the average score of the class is 88 points, so together they scored $88 \cdot(14+16)$ points. According to this, the correct equation is

$$
14 x+16 \cdot 81=88(14+16)
$$

The solution to the last equation is $x=96$, which means that the girls scored an average of 96 points.