Ratio and proportion

  • Six Notes all Nice Ratios
    problem

    Six Notes All Nice Ratios

    Age
    14 to 16
    Challenge level
    1 out of 3

    The Pythagoreans noticed that nice simple ratios of string length made nice sounds together.

  • A Scale for the Solar System
    problem

    A Scale for the Solar System

    Age
    14 to 16
    Challenge level
    1 out of 3

    The Earth is further from the Sun than Venus, but how much further? Twice as far? Ten times?

  • Small tomato seedlings in pink pots.
    problem

    Punky Fish

    Age
    14 to 16
    Challenge level
    1 out of 3

    A male punky fish has 9 stripes and a female punky fish has 8 stripes. I count 86 stripes on the fish in my tank. What is the ratio of male fish to female fish?

  • Mixed up mixture
    problem

    Mixed Up Mixture

    Age
    14 to 16
    Challenge level
    1 out of 3

    Can you fill in the mixed up numbers in this dilution calculation?

  • Small tomato seedlings in pink pots.
    problem

    Meeting Point

    Age
    14 to 16
    Challenge level
    1 out of 3

    Malcolm and Nikki run at different speeds. They set off in opposite directions around a circular track. Where on the track will they meet?

  • Small tomato seedlings in pink pots.
    problem

    Tennis Club

    Age
    14 to 16
    Challenge level
    1 out of 3

    Three-quarters of the junior members of a tennis club are boys and the rest are girls. What is the ratio of boys to girls among these members?

  • Contact
    problem

    Contact

    Age
    14 to 16
    Challenge level
    2 out of 3
    A circular plate rolls in contact with the sides of a rectangular tray. How much of its circumference comes into contact with the sides of the tray when it rolls around one circuit?
  • Gift of Gems
    problem

    Gift of Gems

    Age
    14 to 16
    Challenge level
    2 out of 3

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

  • Small tomato seedlings in pink pots.
    problem

    Burning Down

    Age
    14 to 16
    Challenge level
    2 out of 3

    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
    2 out of 3

    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.