Reasoning, convincing and proving

  • The Genie in the Jar
    problem

    The genie in the jar

    Age
    11 to 14
    Challenge level
    filled star empty star empty star
    This jar used to hold perfumed oil. It contained enough oil to fill granid silver bottles. Each bottle held enough to fill ozvik golden goblets and each goblet held enough to fill vaswik crystal spoons. Each day a spoonful was used to perfume the bath of a beautiful princess. For how many days did the whole jar last? The genie's master replied: Five hundred and ninety five days. What three numbers do the genie's words granid, ozvik and vaswik stand for?
  • Is it Magic or is it Maths?
    problem

    Is it magic or is it maths?

    Age
    11 to 14
    Challenge level
    filled star filled star empty star
    Here are three 'tricks' to amaze your friends. But the really clever trick is explaining to them why these 'tricks' are maths not magic. Like all good magicians, you should practice by trying them. Can you explain how they work?
  • Cross-Country Race
    problem

    Cross-country race

    Age
    14 to 16
    Challenge level
    filled star filled star empty star
    Eight children enter the autumn cross-country race at school. How many possible ways could they come in at first, second and third places?
  • Eleven
    problem

    Eleven

    Age
    11 to 14
    Challenge level
    filled star filled star empty star
    Replace each letter with a digit to make this addition correct.
  • Add 3 Dice
    problem

    Add 3 dice

    Age
    7 to 11
    Challenge level
    filled star filled star empty star
    Three dice are placed in a row. Find a way to turn each one so that the three numbers on top of the dice total the same as the three numbers on the front of the dice. Can you find all the ways to do this?
  • Football crazy Hockey mad
    problem

    Football crazy hockey mad

    Age
    11 to 14
    Challenge level
    filled star empty star empty star
    In a league of 5 football teams which play in a round robin tournament show that it is possible for all five teams to be league leaders.
  • Flight of the Flibbins
    problem

    Flight of the Flibbins

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

    Blue Flibbins are so jealous of their red partners that they will not leave them on their own with any other bue Flibbin. What is the quickest way of getting the five pairs of Flibbins safely to the new planet?

  • Pattern of islands
    problem

    Pattern of islands

    Age
    11 to 14
    Challenge level
    filled star filled star empty star
    In how many distinct ways can six islands be joined by bridges so that each island can be reached from every other island...
  • Dicing with numbers
    problem

    Dicing with numbers

    Age
    11 to 14
    Challenge level
    filled star empty star empty star
    In how many ways can you arrange three dice side by side on a surface so that the sum of the numbers on each of the four faces (top, bottom, front and back) is equal?
  • Not necessarily in that order
    problem

    Not necessarily in that order

    Age
    11 to 14
    Challenge level
    filled star filled star empty star
    Baker, Cooper, Jones and Smith are four people whose occupations are teacher, welder, mechanic and programmer, but not necessarily in that order. What is each person’s occupation?