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    Question

    The average of a set of 's' numbers is 25. If 100 is

    added to the set, then the average of the set becomes 25.2. Find the value of '4 X (s - 9)'.
    A 1460 Correct Answer Incorrect Answer
    B 1480 Correct Answer Incorrect Answer
    C 1450 Correct Answer Incorrect Answer
    D 1470 Correct Answer Incorrect Answer
    E 1490 Correct Answer Incorrect Answer

    Solution

    Sum of all 's' numbers = 25s
    ATQ:
    (25s + 100) / (s + 1) = 25.2
    Multiplying both sides by (s + 1):
    25s + 100 = 25.2(s + 1)
    25s + 100 = 25.2s + 25.2
    100 - 25.2 = 25.2s - 25s
    74.8 = 0.2s
    s = 374
    4 X (s - 9):
    4 X (374 - 9) = 4 X 365 = 1460

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