Multiple choice

Passage

[CAT 1997] Directions for Questions 2 to 4: Answer the questions based on the following information. There are 60 students in a class. These students are divided into three groups A, B and C of 15, 20 and 25 students each. The groups A and C are combined to form group D.

If one student from group A is shifted to group B, which of the following will be true?

  1. The average weight of both groups increases.

  2. The average weight of both the groups decreases.

  3. The average weight of the class remains the same.

  4. Cannot be determined
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Shifting a student from group A to group B changes the individual group averages, but the total number of students and the total weight of the class remain constant. Therefore, the overall class average remains unchanged.

AI explanation

The total number and total weight of the entire class of 60 students remains completely unchanged when a student is merely shifted from one internal group to another. Because the overall sum of weights and the total count are constant, the average weight of the class remains the same.

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