Diophantine equations

  • Deep Roots
    problem

    Deep Roots

    Age
    14 to 16
    Challenge level
    3 out of 3
    Find integer solutions to: $\sqrt{a+b\sqrt{x}} + \sqrt{c+d.\sqrt{x}}=1$
  • Small pepper seedlings in orange pots.
    problem

    Not a Polite Question

    Age
    11 to 14
    Challenge level
    2 out of 3

    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...

  • Small tomato seedlings in pink pots.
    problem

    Whole Numbers Only

    Age
    11 to 14
    Challenge level
    2 out of 3

    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
    2 out of 3

    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?

  • Small tomato seedlings in pink pots.
    problem

    Cakes and Buns

    Age
    11 to 14
    Challenge level
    2 out of 3

    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
    3 out of 3

    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
    1 out of 3

    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
    2 out of 3

    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
    1 out of 3

    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
    1 out of 3

    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.