Simultaneous equations

  • The Simple Life
    problem

    The Simple Life

    Age
    11 to 14
    Challenge level
    filled star filled star empty star

    The answer is $5x+8y$... What was the question?

  • Building Up
    problem

    Not a Polite Question

    Age
    11 to 14
    Challenge level
    filled star filled star empty star

    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
    filled star filled star empty star

    Can you work out how many of each kind of pencil this student bought?

  • Quadruple Clue Sudoku
    problem

    Quadruple Clue Sudoku

    Age
    11 to 16
    Challenge level
    filled star empty star empty star

    Four numbers on an intersection that need to be placed in the surrounding cells. That is all you need to know to solve this sudoku.

  • Another Quadruple Clue Sudoku
    problem

    Another Quadruple Clue Sudoku

    Age
    11 to 16
    Challenge level
    filled star empty star empty star

    This is a variation of sudoku which contains a set of special clue-numbers. Each set of 4 small digits stands for the numbers in the four cells of the grid adjacent to this set.

  • All-Variables Sudoku
    problem

    All-Variables Sudoku

    Age
    11 to 18
    Challenge level
    filled star empty star empty star

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

  • LCM Sudoku II
    problem

    LCM Sudoku II

    Age
    11 to 18
    Challenge level
    filled star empty star empty star

    You are given the Lowest Common Multiples of sets of digits. Find the digits and then solve the Sudoku.