In a class, there are three groups A, B and C. If one student from group A and two students from group B are shifted to group C, then what happens to the average weight of the students of the class?

The average weight of the students of the class is calculated by dividing the total weight of all students in the class by the total number of students in the class.

1. Total Weight of the Class: When students are shifted between groups (A, B, C) within the same class, no students are added to or removed from the class, and no student's weight changes. Therefore, the total weight of all students in the entire class remains constant.

2. Total Number of Students in the Class: Similarly, shifting students between groups within the class does not change the total number of students in the entire class. The total count remains the same.

Since both the total weight of the students in the class and the total number of students in the class remain unchanged, their ratio (the average weight of the class) must also remain unchanged.

Option Analysis: A) increases: Incorrect, as total weight and number are constant. B) decreases: Incorrect, as total weight and number are constant. C) same: Correct, as the total weight and total number of students in the class are unaltered. D) cbd (cannot be determined): Incorrect, because the class average is definitively constant based on the principles of averages.