Inequalities

  • 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?

  • All-Variables Sudoku
    problem

    All-Variables Sudoku

    Age
    11 to 18
    Challenge level
    1 out of 3

    The challenge is to find the values of the variables if you are to solve this Sudoku.

  • Rationals Between...
    problem

    Rationals Between...

    Age
    14 to 16
    Challenge level
    2 out of 3

    What fractions can you find between the square roots of 65 and 67?

  • Mediant madness
    problem

    Mediant Madness

    Age
    14 to 16
    Challenge level
    2 out of 3

    Kyle and his teacher disagree about his test score - who is right?

  • Small pepper seedlings in turquoise pots.
    problem

    Biggest Enclosure

    Age
    14 to 16
    Challenge level
    2 out of 3

    Three fences of different lengths form three sides of an enclosure. What arrangement maximises the area?

  • Small pepper seedlings in orange pots.
    problem

    Near 10

    Age
    14 to 16
    Challenge level
    2 out of 3

    10 must remain within easy reach...

  • Small tomato seedlings in pink pots.
    problem

    Powerful Order

    Age
    14 to 16
    Challenge level
    2 out of 3

    Powers of numbers might look large, but which of these is the largest...

  • Not Continued Fractions
    problem

    Not Continued Fractions

    Age
    14 to 18
    Challenge level
    1 out of 3

    Which rational numbers cannot be written in the form x + 1/(y + 1/z) where x, y and z are integers?

  • ' Tis Whole
    problem

    'tis Whole

    Age
    14 to 18
    Challenge level
    2 out of 3

    Take a few whole numbers away from a triangle number. If you know the mean of the remaining numbers can you find the triangle number and which numbers were removed?

  • 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?