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    Identify the term that does NOT belong to the following series.3T3, 5S5, 9R7, 12P8, 23P11
    Question

    Identify the term that does NOT belong to the following series.
    3T3, 5S5, 9R7, 12P8, 23P11

    A.

    12P8

    B.

    23P11

    C.

    3T3

    D.

    9R7

    Correct option is A

    Given: 3T3, 5S5, 9R7, 12P8, 23P11
    Logic: 
    1st number: adding (+2, +4, +6, 8,...)
    Middle letters:  decreasing by - 1 each time.
    2nd numbers:  increasing by + 2 each time.
    Let's solve it: 
    First numbers: 3 + 2 = 5, 5 + 4 = 9, 9 + 6  =15 ≠ 12, 15 + 8 = 23
    Letters: T - 1 = S, S - 1 = R, R - 1 = Q ≠ P, Q - 1 = P
    Second numbers: 3 + 2 = 5, 5 + 2 = 7, 7 + 2 = 9 ≠ 8, 9 + 2 = 11
    So, the term 12P8 that does NOT belong to the given series.
    Thus, the correct option is (a) 12P8.

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