Marks of a student were wrongly entered as 83 instead of 63 . Due to that the…
2024
Marks of a student were wrongly entered as 83 instead of 63 . Due to that the average marks for the class got increased by 0.5 then the number of students in the class is
Answer: A. 40 — Answer: 40 Let x be the number of students in the class. The wrong entry increased the average by 0.5, so the total increase in the sum of marks = 0.5 × x =…
- A.
40
- B.
20
- C.
10
- D.
73
Attempted by 23 students.
Show answer & explanation
Correct answer: A
Answer: 40
Let x be the number of students in the class.
The wrong entry increased the average by 0.5, so the total increase in the sum of marks = 0.5 × x = 0.5x.
The actual increase in total marks due to the error is 83 − 63 = 20.
Set 0.5x = 20 and solve: x = 20 ÷ 0.5 = 40.
Check: total increase 20 divided by 40 students = 0.5 increase in average, so the solution is consistent.