Diophantine equations

  • Deep Roots
    problem

    Deep Roots

    Age
    14 to 16
    Challenge level
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    Find integer solutions to: $\sqrt{a+b\sqrt{x}} + \sqrt{c+d.\sqrt{x}}=1$
  • Building Up
    problem

    Not a Polite Question

    Age
    11 to 14
    Challenge level
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    When asked how old she was, the teacher replied: My age in years is not prime but odd and when reversed and added to my age you have a perfect square...

  • Whole Numbers Only
    problem

    Whole Numbers Only

    Age
    11 to 14
    Challenge level
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    Can you work out how many of each kind of pencil this student bought?

  • A gold gift box with a ribbon.
    problem

    Plutarch's Boxes

    Age
    11 to 14
    Challenge level
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    According to Plutarch, the Greeks found all the rectangles with integer sides, whose areas are equal to their perimeters. Can you find them? What rectangular boxes, with integer sides, have their surface areas equal to their volumes?

  • Cakes and Buns
    problem

    Cakes and Buns

    Age
    11 to 14
    Challenge level
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    Helen buys some cakes and some buns for her party. Can you work out how many of each she buys?

  • Hallway Borders
    problem

    Hallway Borders

    Age
    11 to 14
    Challenge level
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    What are the possible dimensions of a rectangular hallway if the number of tiles around the perimeter is exactly half the total number of tiles?

  • 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?

  • Upsetting Pitagoras
    problem

    Upsetting Pythagoras

    Age
    14 to 18
    Challenge level
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    Find the smallest integer solution to the equation 1/x^2 + 1/y^2 = 1/z^2

  • 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?

  • 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.