Question
In an examination, the average marks obtained by the
students is 40. After correcting the quantitative mistakes, the average of 50 students is reduced to 25 from 40 and the overall average of the student is reduced to 30. Then find the total number of students who participated in that examination.Solution
Let the total number of students be x Average marks obtained by the students = 40 Total marks = 40x After correcting the quantitative mistakes the average decreased by (40-25) = 15 marks Total reduction = 15 × 50 = 750 Now According to the Question, (40x-750)/x = 30 40x-750=30x x=75 Total number of students = 75
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