Ratio and proportion

  • Five circuits, seven spins
    problem

    Five circuits, seven spins

    Age
    16 to 18
    Challenge level
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    A circular plate rolls inside a rectangular tray making five circuits and rotating about its centre seven times. Find the dimensions of the tray.
  • Golden Ratio
    problem

    Golden ratio

    Age
    16 to 18
    Challenge level
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    Solve an equation involving the Golden Ratio phi where the unknown occurs as a power of phi.