The average score of a group of n students in a mathematics competition is 60. A series of adjustments is made to the data. The top 25% of students (by score) are removed from the data set. Their average score was 80. A new group of 10 students joins the remaining group. This new group has an average score of 40. After these changes, it was discovered that a score belonging to one of the original remaining students was misrecorded as 100 instead of 80. After all departures, additions, and corrections, the final average score of the group is exactly 50. What was the original number of students (n)?
Last updated Jul 21, 2026