2017 · Q52
The mean marks obtained by 300 students in a subject are 60. The mean of top 100 students was found to be 80 and the mean of last 100 students was found to be 50. The mean marks of the remaining 100 students are
Elementary MathematicsStatistics
- A70
- B65
- C60
- D50
Explanation
Total = 300 × 60 = 18000 marks. Top 100 give 8000, last 100 give 5000, leaving 5000 for the middle 100 — mean 50: option D.