In the math test of class 5 and class 2, the average score of the whole class is 92, the average score of boys is 98, and that of boys is 24. How many girls are there?
98-92=6 means that the average score of boys is higher than that of girls, and 24×6= 144 means that the total score of boys is higher than that of girls. Without the total number of classes, there will be more girls, as long as the total number of girls plus 24×6= 144 divided by the number of girls. For example, the average score of girls is 86, so there are many girls.