Question
In an examination, the average marks obtained by the
students is 75. After correcting the quantitative mistakes, the average of 100 students is reduced to 60 from 75 and the overall average of the student is reduced to 70. 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 = 75 Total marks = 75x After correcting the quantitative mistakes the average decreased by (75-60) = 15 marks Total reduction = 15 × 100 = 1500 Now According to the Question, (75x-1500)/x = 70 70x = 75x – 1500 X = 300 Total number of students = 300
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