Creating and manipulating expressions and formulae

  • AMGM
    problem

    AMGM

    Age
    14 to 16
    Challenge level
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    Can you use the diagram to prove the AM-GM inequality?

  • Lap Times
    problem

    Lap times

    Age
    14 to 16
    Challenge level
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    Can you find the lap times of the two cyclists travelling at constant speeds?
  • Really Mr. Bond
    problem

    Really Mr. Bond

    Age
    14 to 16
    Challenge level
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    115^2 = (110 x 120) + 25, that is 13225 895^2 = (890 x 900) + 25, that is 801025 Can you explain what is happening and generalise?

  • Back to Basics
    problem

    Back to basics

    Age
    14 to 16
    Challenge level
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    Find b where 3723(base 10) = 123(base b).
  • Square pizza
    problem

    Square pizza

    Age
    14 to 16
    Challenge level
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    Can you show that you can share a square pizza equally between two people by cutting it four times using vertical, horizontal and diagonal cuts through any point inside the square?
  • Semi-Square
    problem

    Semi-square

    Age
    14 to 16
    Challenge level
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    What is the ratio of the area of a square inscribed in a semicircle to the area of the square inscribed in the entire circle?
  • Poly Fibs
    problem

    Poly fibs

    Age
    16 to 18
    Challenge level
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    A sequence of polynomials starts 0, 1 and each poly is given by combining the two polys in the sequence just before it. Investigate and prove results about the roots of the polys.
  • Triangles within Pentagons
    problem

    Triangles within pentagons

    Age
    14 to 16
    Challenge level
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    Show that all pentagonal numbers are one third of a triangular number.
  • Cubes within Cubes revisited
    problem

    Cubes within cubes revisited

    Age
    11 to 14
    Challenge level
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    Imagine starting with one yellow cube and covering it all over with a single layer of red cubes, and then covering that cube with a layer of blue cubes. How many red and blue cubes would you need?
  • Integer Indices
    problem

    Integer indices

    Age
    14 to 16
    Challenge level
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    From this sum of powers, can you find the sum of the indices?