Question

    The average age of a class of 25 girls is 20 years. If 7

    new girls having average age of 12 years join the class, then the average age of the class becomes:
    A 18.25 years Correct Answer Incorrect Answer
    B 13.6 years Correct Answer Incorrect Answer
    C 16.5 years Correct Answer Incorrect Answer
    D 19 years Correct Answer Incorrect Answer

    Solution

    Total age of 25 girls = 25 × 20 = 500 years Total age of 32 girls = 500 + (7 × 12) = 500 + 84 = 584 years Therefore new average age = 584/32 = 18.25 years

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