Several students have taken an exam. There was an error in the answer key which affected the marks of 48 students and their average marks reduced from 78 to 66. The average of remaining students increased by 3.5 marks. Due to this the average of all students reduced by 4.5 marks. The number of students that attended the exam is.

93

Average of affected students decreased by = 78 - 66 = 12

Average of non affected students increased by = 3.5

Average of all students decreased by = 4.5

ATQ,