Ratio and proportion

  • Small tomato seedlings in pink pots.
    problem

    Tyre Wear

    Age
    11 to 14
    Challenge level
    2 out of 3

    A car with 5 tyres (four road tyres and a spare) travelled 30,000 km. All 5 tyres were used equally. How many kilometres' wear did each tyre receive?

  • Small tomato seedlings in pink pots.
    problem

    Washing Elephants

    Age
    11 to 14
    Challenge level
    3 out of 3

    How long will it take Mary and Nigel to wash an elephant if they work together?

  • Square Pegs
    problem

    Square Pegs

    Age
    11 to 14
    Challenge level
    3 out of 3

    Which is a better fit, a square peg in a round hole or a round peg in a square hole?

  • Do unto Caesar
    problem

    Do Unto Caesar

    Age
    11 to 14
    Challenge level
    3 out of 3

    At the beginning of the night three poker players; Alan, Bernie and Craig had money in the ratios 7 : 6 : 5. At the end of the night the ratio was 6 : 5 : 4. One of them won $1 200. What were the assets of the players at the beginning of the evening?

  • Hello Again
    problem

    Hello Again

    Age
    11 to 14
    Challenge level
    3 out of 3

    Anne completes a circuit around a circular track in 40 seconds. Brenda runs in the opposite direction and meets Anne every 15 seconds. How long does it take Brenda to run around the track?

  • Small pepper seedlings in turquoise pots.
    problem

    Hexagon Slices

    Age
    11 to 14
    Challenge level
    3 out of 3

    Weekly Problem 37 - 2007
    This regular hexagon has been divided into four trapezia and one hexagon.... what is the ratio of the lengths of sides p, q and r?

  • Star Gazing
    problem

    Star Gazing

    Age
    14 to 16
    Challenge level
    1 out of 3

    Find the ratio of the outer shaded area to the inner area for a six pointed star and an eight pointed star.

  • Conical Bottle
    problem

    Conical Bottle

    Age
    14 to 16
    Challenge level
    1 out of 3

    A right circular cone is filled with liquid to a depth of half its vertical height. The cone is inverted. How high up the vertical height of the cone will the liquid rise?

  • A Shade Crossed
    problem

    A Shade Crossed

    Age
    14 to 16
    Challenge level
    1 out of 3

    Find the area of the shaded region created by the two overlapping triangles in terms of a and b?

  • ArRh!
    problem

    ArRh!

    Age
    14 to 16
    Challenge level
    1 out of 3

    Triangle ABC is equilateral. D, the midpoint of BC, is the centre of the semi-circle whose radius is R which touches AB and AC, as well as a smaller circle with radius r which also touches AB and AC. What is the value of r/R?