Question

    The average age of a class of 25 girls is 16 years. If 5

    new girls having average age of 10 years join the class, then the average age of the class becomes:
    A 12 years Correct Answer Incorrect Answer
    B 13.6 years Correct Answer Incorrect Answer
    C 15 years Correct Answer Incorrect Answer
    D 19 years Correct Answer Incorrect Answer

    Solution

    Total age of 25 girls = 25 × 15 = 400 years Total age of 30 girls = 400 + (5 × 10) = 400 + 50 = 450 years Therefore new average age = 450/30 = 15 years

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