Simultaneous equations

  • All-Variables Sudoku
    problem

    All-Variables Sudoku

    Age
    11 to 18
    Challenge level
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    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
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    You are given the Lowest Common Multiples of sets of digits. Find the digits and then solve the Sudoku.

  • Warmsnug Double Glazing
    problem
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    Warmsnug Double Glazing

    Age
    14 to 16
    Challenge level
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    How have "Warmsnug" arrived at the prices shown on their windows? Which window has been given an incorrect price?

  • Which is cheaper?
    problem
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    Which Is Cheaper?

    Age
    14 to 16
    Challenge level
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    When I park my car in Mathstown, there are two car parks to choose from. Can you help me to decide which one to use?

  • Building Tetrahedra
    problem

    Building Tetrahedra

    Age
    14 to 16
    Challenge level
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    Can you make a tetrahedron whose faces all have the same perimeter?
  • Gift of Gems
    problem

    Gift of Gems

    Age
    14 to 16
    Challenge level
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    Four jewellers share their stock. Can you work out the relative values of their gems?
  • CD Heaven
    problem
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    CD Heaven

    Age
    14 to 16
    Challenge level
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    All CD Heaven stores were given the same number of a popular CD to sell for £24. In their two week sale each store reduces the price of the CD by 25% ... How many CDs did the store sell at each price?

  • Day of the Triffids
    problem

    Day of the Triffids

    Age
    14 to 16
    Challenge level
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    Jasmine buys three different types of plant. How many triffids did she buy?

  • Matchless
    problem
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    Matchless

    Age
    14 to 16
    Challenge level
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    There is a particular value of x, and a value of y to go with it, which make all five expressions equal in value. Can you find that x, y pair?