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    Which of the following numbers will replace the question mark (?) in the given series? 65, 90, 107, 116, 121, ?
    Question

    Which of the following numbers will replace the question mark (?) in the given series?
    65, 90, 107, 116, 121, ?

    A.

    123

    B.

    125

    C.

    122

    D.

    124

    Correct option is C

    Given:
    65, 90, 107, 116, 121, ?
    Logic: +(52+0), + (42+1), +(32+0), +(22+1), +(12+0),.....
    90 - 65 = +(52+0) = 25
    107 - 90 = (42+1) = 17
    116 - 107 = +(32+0) = 9
    121 - 116 = +(22+1) = 5 
    ? - 121 = +(12+0) = 1 
    ? = 121 + 1 
    ? = 122
    So the next number is : 121+1 = 122
    Thus the correct answer is (C)

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