Probability

  • Knock-out
    problem
    Favourite

    Knock-Out

    Age
    16 to 18
    Challenge level
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    Before a knockout tournament with 2^n players I pick two players. What is the probability that they have to play against each other at some point in the tournament?
  • Coin Tossing Games
    problem

    Coin Tossing Games

    Age
    14 to 16
    Challenge level
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    You and I play a game involving successive throws of a fair coin. Suppose I pick HH and you pick TH. The coin is thrown repeatedly until we see either two heads in a row (I win) or a tail followed by a head (you win). What is the probability that you win?
  • Win or Lose?
    problem

    Win or Lose?

    Age
    14 to 16
    Challenge level
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    A gambler bets half the money in his pocket on the toss of a coin, winning an equal amount for a head and losing his money if the result is a tail. After 2n plays he has won exactly n times. Has he more money than he started with?
  • Master Minding
    problem

    Master Minding

    Age
    11 to 14
    Challenge level
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    Your partner chooses two beads and places them side by side behind a screen. What is the minimum number of guesses you would need to be sure of guessing the two beads and their positions?
  • Taking Chances
    problem

    Taking Chances

    Age
    11 to 14
    Challenge level
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    This article, for students and teachers, is mainly about probability, the mathematical way of looking at random chance and is a shorter version of Taking Chances Extended.
  • Can't find a coin?
    problem

    Can't Find a Coin?

    Age
    11 to 14
    Challenge level
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    Can you generate a set of random results? Can you fool the random simulator?
  • Heavy hydrocarbons
    problem

    Heavy Hydrocarbons

    Age
    14 to 18
    Challenge level
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    Explore the distribution of molecular masses for various hydrocarbons
  • Molecular sequencer
    problem

    Molecular Sequencer

    Age
    14 to 18
    Challenge level
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    Investigate the molecular masses in this sequence of molecules and deduce which molecule has been analysed in the mass spectrometer.
  • Peas in a pod
    problem

    Peas in a Pod

    Age
    14 to 16
    Challenge level
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    What is the chance this pea plant will look like its parents?
  • Squash
    problem

    Squash

    Age
    16 to 18
    Challenge level
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    If the score is 8-8 do I have more chance of winning if the winner is the first to reach 9 points or the first to reach 10 points?