Question
The average marks of all the students decreased by 5
when it was found that marks of one of the students were wrongly taken as 95 instead of 45. Find the total number of students.Solution
Let number of students be 'N' and sum of marks of all the students be 'S'. ATQ: We have, (S−95+45)/N = (S/N) - 5 Or, (S/N) - (S−50)/N = 5 Or, (50/N) = 5 So, 'N' = (50 / 5) = 10 Therefore, total number of students are 10.
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