Project ForgeGeneral Aptitude
Quantitative Aptitude
GATE 2025
Medium
The average marks obtained by a class in an examination were calculated as 30.8. However, while checking the marks entered, the teacher found that the marks of one student were entered incorrectly as 24 instead of 42. After correcting the marks, the average becomes 31.4. How many students does the class have?
- A25
- B28
- 30
- D32
Explanation
The correction adds (42 − 24) = 18 marks to the total, raising the average by 31.4 − 30.8 = 0.6. So 18/n = 0.6, giving n = 18/0.6 = 30 students.
Source: GATE CS 2025 (Session 1 / CS1) (2025)
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