Creating and manipulating expressions and formulae

  • Harmonic Triangle
    problem
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    Harmonic Triangle

    Age
    14 to 16
    Challenge level
    3 out of 3

    Can you see how to build a harmonic triangle? Can you work out the next two rows?

  • Dating made Easier
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    Dating Made Easier

    Age
    14 to 16
    Challenge level
    3 out of 3

    If a sum invested gains 10% each year how long before it has doubled its value?

  • Unit Interval
    problem
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    Unit Interval

    Age
    14 to 18
    Challenge level
    1 out of 3

    Take any two numbers between 0 and 1. Prove that the sum of the numbers is always less than one plus their product?

  • Always Two
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    Always Two

    Age
    14 to 18
    Challenge level
    2 out of 3

    Find all the triples of numbers a, b, c such that each one of them plus the product of the other two is always 2.

  • Iff
    problem
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    Iff

    Age
    14 to 18
    Challenge level
    2 out of 3

    Take a triangular number, multiply it by 8 and add 1. What is special about your answer? Can you prove it?

  • Always Perfect
    problem
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    Always Perfect

    Age
    14 to 18
    Challenge level
    2 out of 3

    Show that if you add 1 to the product of four consecutive numbers the answer is ALWAYS a perfect square.

  • Leonardo's Problem
    problem
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    Leonardo's Problem

    Age
    14 to 18
    Challenge level
    3 out of 3

    A, B & C own a half, a third and a sixth of a coin collection. Each grab some coins, return some, then share equally what they had put back, finishing with their own share. How rich are they?

  • Polynomial Relations
    problem
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    Polynomial Relations

    Age
    16 to 18
    Challenge level
    1 out of 3

    Given any two polynomials in a single variable it is always possible to eliminate the variable and obtain a formula showing the relationship between the two polynomials. Try this one.

  • How Many Solutions?
    problem
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    How Many Solutions?

    Age
    16 to 18
    Challenge level
    1 out of 3

    Find all the solutions to the this equation.

  • Quadratic Harmony
    problem
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    Quadratic Harmony

    Age
    16 to 18
    Challenge level
    1 out of 3

    Find all positive integers a and b for which the two equations: x^2-ax+b = 0 and x^2-bx+a = 0 both have positive integer solutions.