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    Question

    Find the missing number in the given number series.

    3, 7, 18, 38, 69, ?
    A 100 Correct Answer Incorrect Answer
    B 125 Correct Answer Incorrect Answer
    C 113 Correct Answer Incorrect Answer
    D 133 Correct Answer Incorrect Answer
    E None of these Correct Answer Incorrect Answer

    Solution

    ATQ,

    First differences:

    7 - 3 = 4

    18 - 7 = 11

    38 - 18 = 20

    69 - 38 = 31

    Now, second differences:

    11 - 4 = 7

    20 - 11 = 9

    31 - 20 = 11 → increases by 2 each time

    Next second difference = 13

    So, next first difference = 31 + 13 = 44

    Next term = 69 + 44 = 113

    Hence, missing number is 113

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