Simultaneous equations

  • Building Tetrahedra
    problem

    Building Tetrahedra

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

    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
    filled star filled star empty star

    Four jewellers share their stock. Can you work out the relative values of their gems?

  • Day of the Triffids
    problem

    Day of the Triffids

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

    Jasmine buys three different types of plant. How many triffids did she buy?

  • Table Height
    problem

    Table Height

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

    A table has blocks of wood placed on and next to it. Can you work out how tall it is?

  • Packing Boxes
    problem

    Packing Boxes

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

    Look at the times that Harry, Christine and Betty take to pack boxes when working in pairs, to find how fast Christine can pack boxes by herself.

  • Polycircles
    problem

    Polycircles

    Age
    14 to 16
    Challenge level
    filled star filled star filled star

    Show that for any triangle it is always possible to construct 3 touching circles with centres at the vertices. Is it possible to construct touching circles centred at the vertices of any polygon?

  • Symmetricality
    problem

    Symmetricality

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

    Five equations and five unknowns. Is there an easy way to find the unknown values?

  • Overturning fracsum
    problem

    Overturning Fracsum

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

    Can you solve the system of equations to find the values of x, y and z?

  • Pair Squares
    problem

    Pair Squares

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

    The sum of any two of the numbers 2, 34 and 47 is a perfect square. Choose three square numbers and find sets of three integers with this property. Generalise to four integers.

  • How Many Balls?
    problem

    How Many Balls?

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

    A bag contains red and blue balls. You are told the probabilities of drawing certain combinations of balls. Find how many red and how many blue balls there are in the bag.