Ratio and proportion

  • 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?

  • Burning down
    problem

    Burning Down

    Age
    14 to 16
    Challenge level
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    One night two candles were lit. Can you work out how long each candle was originally?

  • Rhombus in Rectangle
    problem

    Rhombus in Rectangle

    Age
    14 to 16
    Challenge level
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    Take any rectangle ABCD such that AB > BC. The point P is on AB and Q is on CD. Show that there is exactly one position of P and Q such that APCQ is a rhombus.

  • Tin Tight
    problem

    Tin Tight

    Age
    14 to 16
    Challenge level
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    What's the most efficient proportion for a 1 litre tin of paint?

  • Square Ratio
    problem

    Square Ratio

    Age
    14 to 16
    Challenge level
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    A square is divided into four rectangles and a square. Can you work out the ratio of the side lengths of the rectangles?

  • Pythagoras’ Comma
    problem

    Pythagoras' Comma

    Age
    14 to 16
    Challenge level
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    Using an understanding that 1:2 and 2:3 were good ratios, start with a length and keep reducing it to 2/3 of itself. Each time that took the length under 1/2 they doubled it to get back within range.

  • Eight Ratios
    problem

    Eight Ratios

    Age
    14 to 16
    Challenge level
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    Two perpendicular lines lie across each other and the end points are joined to form a quadrilateral. Eight ratios are defined, three are given but five need to be found.

  • Shepherd's Flock
    problem

    Shepherd's Flock

    Age
    14 to 16
    Challenge level
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    Does Joseph have too many sheep in his flock...

  • The Fastest Cyclist
    problem

    The Fastest Cyclist

    Age
    14 to 16
    Challenge level
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    Andy is desperate to reach John o'Groats first. Can you devise a winning race plan?

  • From all corners
    problem

    From All Corners

    Age
    14 to 16
    Challenge level
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    Straight lines are drawn from each corner of a square to the mid points of the opposite sides. Express the area of the octagon that is formed at the centre as a fraction of the area of the square.