Diophantine equations

  • Why stop at Three by One
    article

    Why stop at three by one

    Beautiful mathematics. Two 18 year old students gave eight different proofs of one result then generalised it from the 3 by 1 case to the n by 1 case and proved the general result.

  • Euclid's Algorithm I
    article

    Euclid's algorithm I

    How can we solve equations like 13x + 29y = 42 or 2x +4y = 13 with the solutions x and y being integers? Read this article to find out.

  • Euclid's Algorithm II
    article

    Euclid's algorithm II

    We continue the discussion given in Euclid's Algorithm I, and here we shall discover when an equation of the form ax+by=c has no solutions, and when it has infinitely many solutions.

  • Shades of Fermat's Last Theorem
    problem

    Shades of Fermat's Last Theorem

    Age
    16 to 18
    Challenge level
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    The familiar Pythagorean 3-4-5 triple gives one solution to (x-1)^n + x^n = (x+1)^n so what about other solutions for x an integer and n= 2, 3, 4 or 5?

  • Rudolff's Problem
    problem

    Rudolff's problem

    Age
    14 to 16
    Challenge level
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    A group of 20 people pay a total of £20 to see an exhibition. The admission price is £3 for men, £2 for women and 50p for children. How many men, women and children are there in the group?
  • Some Cubes
    problem

    Some cubes

    Age
    16 to 18
    Challenge level
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    The sum of the cubes of two numbers is 7163. What are these numbers?
  • Code to Zero
    problem

    Code to zero

    Age
    16 to 18
    Challenge level
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    Find all 3 digit numbers such that by adding the first digit, the square of the second and the cube of the third you get the original number, for example 1 + 3^2 + 5^3 = 135.
  • Our Ages
    problem

    Our ages

    Age
    14 to 16
    Challenge level
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    I am exactly n times my daughter's age. In m years I shall be ... How old am I?
  • Double Angle Triples
    problem

    Double angle triples

    Age
    16 to 18
    Challenge level
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    Try out this geometry problem involving trigonometry and number theory
  • Lattice Points
    problem

    Lattice points

    Age
    16 to 18
    Challenge level
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    Why are there only a few lattice points on a hyperbola and infinitely many on a parabola?