Question:

The average weight of 24 students in a class is 52 kg. If the weight of the teacher is added, the average increases by 1 kg. Find the weight of the teacher.

Show Hint

Whenever one person is added, first calculate the old total and the new total. The difference gives the weight (or marks) of the added person.
Updated On: Jun 8, 2026
  • \(76\) kg
  • \(77\) kg
  • \(75\) kg
  • \(53\) kg
Show Solution
collegedunia
Verified By Collegedunia

The Correct Option is B

Solution and Explanation

Concept: Average is defined as \[ \text{Average} = \frac{\text{Total Sum}}{\text{Number of Observations}}. \] When a new member is added to a group, the total sum changes and therefore the average changes.

Step 1: Calculate the total weight of the students.
Number of students \[ =24 \] Average weight \[ =52 \text{ kg} \] Therefore, \[ \text{Total weight} = 24\times52 = 1248 \text{ kg}. \]

Step 2: Find the new total weight after adding the teacher.
The average increases by \(1\) kg. Hence new average \[ =53 \text{ kg}. \] Total persons \[ =24+1=25. \] Therefore, \[ \text{New Total Weight} = 25\times53 = 1325 \text{ kg}. \]

Step 3: Calculate the teacher's weight.
\[ \text{Teacher's Weight} = 1325-1248 = 77 \text{ kg}. \] Thus, \[ \boxed{77\text{ kg}} \]
Was this answer helpful?
0
0