Question

    What is the average of the squares of the first 17 natural

    numbers?
    A 95 Correct Answer Incorrect Answer
    B 100 Correct Answer Incorrect Answer
    C 105 Correct Answer Incorrect Answer
    D 110 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
    = (17 + 1) × (2 × 17 + 1) ÷ 6
    = 18 × 35 ÷ 6
    = 105

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