Question 16

Explanation

To solve this problem easily, we use the principle of Sum of Values Balance. The combined total score must equal the sum of the total scores of each group.

Let $n$ be the initial number of students. We can set up an equation based on the total values as follows:

Next, we solve this simple linear equation. Notice how we group the terms containing $n$.

Thus, the number of students before being combined is $40$.