New SIDBI Grade A New Batch Starts on Nov 18

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    Question

    The average age of a class of 27 girls is 18 years. If 3 new girls having average age of 8 years join the class, then the average age of the class becomes:

    A 9.5 years Correct Answer Incorrect Answer
    B 17 years Correct Answer Incorrect Answer
    C 11.5 years Correct Answer Incorrect Answer
    D 13 years Correct Answer Incorrect Answer

    Solution

    Total age of 27 girls = 27 × 18 = 486 years Total age of 30 girls = 486 + (3 × 8) = 510 years Therefore new average age = 510/30 = 17 years

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