There are 50 students in a class. In a math exam, the average score of the top 30 students is 12 points higher than that of the bottom 30 students. One student added the average score of the top 30 students The average score of the last 20 points, divided by 2, mistakenly thinks that this is the average score of the class. How much has he increased (or decreased) compared with the average score of the whole class? The average score of the last 20 points, divided by 2, mistakenly thinks that this is the average score of the class. How much has he increased (or decreased) compared with the average score of the whole class? It's urgent!

There are 50 students in a class. In a math exam, the average score of the top 30 students is 12 points higher than that of the bottom 30 students. One student added the average score of the top 30 students The average score of the last 20 points, divided by 2, mistakenly thinks that this is the average score of the class. How much has he increased (or decreased) compared with the average score of the whole class? The average score of the last 20 points, divided by 2, mistakenly thinks that this is the average score of the class. How much has he increased (or decreased) compared with the average score of the whole class? It's urgent!

Hello, I'm glad to answer your question! There are 50 students in a class. After a math exam, they ranked according to their scores. As a result, the average score of the top 30 students is 12 points higher than that of the bottom 20 students