Summation of series

  • Harmonically
    problem

    Harmonically

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

    Production equation

    Age
    16 to 18
    Challenge level
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    Each week a company produces X units and sells p per cent of its stock. How should the company plan its warehouse space?
  • Picturing Square Numbers
    problem

    Picturing square numbers

    Age
    11 to 14
    Challenge level
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    Square numbers can be represented as the sum of consecutive odd numbers. What is the sum of 1 + 3 + ..... + 149 + 151 + 153?

  • Clickety Click and all the Sixes
    problem

    Clickety click and all the sixes

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

    Seriesly

    Age
    16 to 18
    Challenge level
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    Prove that k.k! = (k+1)! - k! and sum the series 1.1! + 2.2! + 3.3! +...+n.n!
  • Reciprocal Triangles
    problem

    Reciprocal triangles

    Age
    16 to 18
    Challenge level
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    Prove that the sum of the reciprocals of the first n triangular numbers gets closer and closer to 2 as n grows.
  • More Polynomial Equations
    problem

    More polynomial equations

    Age
    16 to 18
    Challenge level
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    Find relationships between the polynomials a, b and c which are polynomials in n giving the sums of the first n natural numbers, squares and cubes respectively.
  • Picture Story
    problem

    Picture story

    Age
    14 to 16
    Challenge level
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    Can you see how this picture illustrates the formula for the sum of the first six cube numbers?
  • Summats Clear
    problem

    Summats clear

    Age
    16 to 18
    Challenge level
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    Find the sum, f(n), of the first n terms of the sequence: 0, 1, 1, 2, 2, 3, 3........p, p, p +1, p + 1,..... Prove that f(a + b) - f(a - b) = ab.