Ratio and proportion

  • How big?
    problem

    How big?

    Age
    11 to 14
    Challenge level
    filled star filled star empty star
    If the sides of the triangle in the diagram are 3, 4 and 5, what is the area of the shaded square?
  • One and three
    problem

    One and three

    Age
    14 to 16
    Challenge level
    filled star filled star empty star
    Two motorboats travelling up and down a lake at constant speeds leave opposite ends A and B at the same instant, passing each other, for the first time 600 metres from A, and on their return, 400 metres from B. How long is the lake?
  • Same Height
    problem

    Same height

    Age
    14 to 16
    Challenge level
    filled star filled star filled star
    A trapezium is divided into four triangles by its diagonals. Can you work out the area of the trapezium?
  • Star Gazing
    problem

    Star gazing

    Age
    14 to 16
    Challenge level
    filled star empty star empty star
    Find the ratio of the outer shaded area to the inner area for a six pointed star and an eight pointed star.
  • From all corners
    problem

    From all corners

    Age
    14 to 16
    Challenge level
    filled star filled star filled star
    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.
  • Square Pegs
    problem

    Square pegs

    Age
    11 to 14
    Challenge level
    filled star filled star filled star
    Which is a better fit, a square peg in a round hole or a round peg in a square hole?
  • Rule of Three
    problem

    Rule of three

    Age
    11 to 14
    Challenge level
    filled star empty star empty star
    If it takes four men one day to build a wall, how long does it take 60,000 men to build a similar wall?
  • Two Ladders
    problem

    Two ladders

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

    Two ladders are propped up against facing walls. At what height do the ladders cross?

  • Burning down
    problem

    Burning down

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