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    Which of the following numbers will replace the question mark (?) in the given series? 24, 28, 35, 48, 73, ?
    Question

    Which of the following numbers will replace the question mark (?) in the given series?
    24, 28, 35, 48, 73, ?

    A.

    122

    B.

    121

    C.

    120

    D.

    123

    Correct option is A

    Given:
    24, 28, 35, 48, 73, ?
    Logic:
    Difference of two constitutive number is increasing from 4, 7, 13, 25.
    28 - 24 = 4
    35- 28 = 7 
    48 - 35 = 13
    73 - 48 = 25
    Differences between these differences:
    7 -4 = 3
    13 - 7 = 6
    25 - 13 = 12
    Second differences are: 3, 6, 12. The second differences are doubling 
    the next difference should be 12 + 12 = 24
    The next difference in the original series will be 25 + 24 = 49 
    the next term in the series, add the difference (49) to the last term (73)
    73+ 49 = 122
    Thus, correct option is (a)
    Alternate:
    The second differences are doubling 12+12 = 24
    Add the difference (49) to the last term (73)
    Thus, correct option is (a)​​

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