New RBI Grade B 2025 Notification will come Soon! Enroll Here

    Question

    In an examination, the average marks obtained by the

    students is 85. After correcting the quantitative mistakes, the average of 100 students is reduced to 70 from 85 and the overall average of the student is reduced to 80. Then find the total number of students who participated in that examination?
    A 200 Correct Answer Incorrect Answer
    B 250 Correct Answer Incorrect Answer
    C 300 Correct Answer Incorrect Answer
    D 350 Correct Answer Incorrect Answer

    Solution

    Let the total number of students be x Average marks obtained by the students = 85 Total marks = 85x After correcting the quantitative mistakes the average decreased by (85 - 70) = 15 marks Total reduction = 15 × 100 = 1500 Now According to the Question, (85x - 1500)/x = 80 80x = 85x – 1500 x = 300 Total number of students = 300
    Alternate method: By alligation method, Total number of students = 200+100 = 300

    Practice Next

    Relevant for Exams: