Summation of series

  • Harmonically
    problem
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    Harmonically

    Age
    16 to 18
    Challenge level
    3 out of 3
    Is it true that a large integer m can be taken such that: 1 + 1/2 + 1/3 + ... +1/m > 100 ?
  • Pocket money
    problem
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    Pocket Money

    Age
    11 to 14
    Challenge level
    1 out of 3

    Which of these pocket money systems would you rather have?

  • Picturing Square Numbers
    problem
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    Picturing Square Numbers

    Age
    11 to 14
    Challenge level
    1 out of 3

    Square numbers can be represented as the sum of consecutive odd numbers. What is the sum of 1 + 3 + ..... + 149 + 151 + 153?

  • Double Trouble
    problem
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    Double Trouble

    Age
    14 to 16
    Challenge level
    1 out of 3

    Simple additions can lead to intriguing results...

  • Picture Story
    problem
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    Picture Story

    Age
    14 to 16
    Challenge level
    2 out of 3

    Can you see how this picture illustrates the formula for the sum of the first six cube numbers?

  • Summing geometric progressions
    problem
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    Summing Geometric Progressions

    Age
    14 to 18
    Challenge level
    1 out of 3

    Watch the video to see how to sum the sequence. Can you adapt the method to sum other sequences?

  • The Root of the Problem
    problem
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    The Root of the Problem

    Age
    14 to 18
    Challenge level
    2 out of 3

    Find the sum of this series of surds.

  • Clickety Click and all the Sixes
    problem
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    Clickety Click and All the Sixes

    Age
    16 to 18
    Challenge level
    1 out of 3
    What is the sum of: 6 + 66 + 666 + 6666 ............+ 666666666...6 where there are n sixes in the last term?
  • Telescoping series
    problem
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    Telescoping Series

    Age
    16 to 18
    Challenge level
    2 out of 3

    Find $S_r = 1^r + 2^r + 3^r + ... + n^r$ where r is any fixed positive integer in terms of $S_1, S_2, ... S_{r-1}$.

  • Clickety Click
    problem

    Clickety Click

    Age
    16 to 18
    Challenge level
    1 out of 3
    What is the sum of: 6 + 66 + 666 + 6666 ............+ 666666666...6 where there are n sixes in the last term?