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  • Perplex
    IB Math AIHL
    /
    Sequences & Series
    /

    Problem Bank

    [Maximum mark: 10]

    Let ​Sn​​ be the sum of the first ​n​ terms of an arithmetic sequence with first term ​u1​​ and common difference ​d, where ​u1​>d.


    ​S1​,S3​​ and ​S8​​ are consecutive terms in a geometric sequence with common ratio ​r.

    1. Find the value of ​r.

      [6]

      To earn a crown, get your answer ready before you reveal the options!

    It is given that the first term of the arithmetic sequence is ​3, and that the sum of the first ​k​ terms of the geometric series is greater than ​104.

    1. Find the smallest possible value of ​k.

      [4]

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