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    Question

    What is the average of the squares of the first 47

    natural numbers?
    A 720 Correct Answer Incorrect Answer
    B 740 Correct Answer Incorrect Answer
    C 760 Correct Answer Incorrect Answer
    D 780 Correct Answer Incorrect Answer

    Solution

    Sum of squares of first 'n' natural numbers = n × (n + 1) × (2n + 1) ÷ 6
    So, average = n × (n + 1) × (2n + 1) ÷ 6n = (n + 1) × (2n + 1) ÷ 6
    = (47 + 1) × (2 × 47 + 1) ÷ 6
    = 48 × 95 ÷ 6
    = 760

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