Grades in Slovakia are assigned using numbers from 1, the best, to 5, the worst. In one Slovak school, a test didn't turn out very well in one class. The average grade was 4. The boys did a little better, their average grade was 3.6. The average grade of the girls was 4.2. Which of the following statements about the class is correct? So let's write out this expression for the average grade in terms of the average grade of the boys and the average grade of the girls. So if there are B boys and G girls, that means the total sum of the boys is 3.6B, and the total sum of the girls' grades is 4.2G. So that means the total sum of everyone is 3.6B plus 4.2G. Now if we divide that by the number of people in total, we should get 4, because that's the average overall. So now we have 3.6B and then more than 3.6G. So if we pull out a 3.6G out of here, well this turns into 3.6 plus, you know, whatever is remaining, which is 0.6G, is 4. We'll now subtract and divide by 0.6, and we get that G over B plus G is two-thirds. That means the girls are two-thirds of the class, while the boys have to be the remaining one-third of the class, which means that there are twice as many girls as there are boys.

Slovak class

average grade

boys and girls

grade calculation

student ratio