New Enroll in RBI Grade B New Batch - Starts on May 21

    Question

    Sum of squares of three consecutive numbers is 1325.

    Find the sum of first and third number.
    A 42 Correct Answer Incorrect Answer
    B 30 Correct Answer Incorrect Answer
    C 34 Correct Answer Incorrect Answer
    D 46 Correct Answer Incorrect Answer

    Solution

    Let the numbers be (x – 1), x and (x + 1) => (x – 1)2 + x2 + (x + 1)2 = 1325 => x2 – 2x + 1 + x2 + x2 + 2x + 1 = 1325 => 3x2 = 1325 - 2 => x2 = 1323/3 => x2 = 441 => x = 21 Required sum = (21 – 1) + (21 + 1) = 42

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