Probability

  • Odds and Evens made fair
    problem
    Favourite

    Odds and Evens Made Fair

    Age
    14 to 16
    Challenge level
    2 out of 3

    In this follow-up to the problem Odds and Evens, we invite you to analyse a probability situation in order to find the general solution for a fair game.

  • Which spinners?
    problem
    Favourite

    Which Spinners?

    Age
    14 to 18
    Challenge level
    1 out of 3

    Can you work out which spinners were used to generate the frequency charts?

  • Snooker Frames
    problem
    Favourite

    Snooker Frames

    Age
    16 to 18
    Challenge level
    1 out of 3

    It is believed that weaker snooker players have a better chance of winning matches over eleven frames (i.e. first to win 6 frames) than they do over fifteen frames. Is this true?

  • Teams
    problem
    Favourite

    Teams

    Age
    16 to 18
    Challenge level
    1 out of 3

    Two brothers belong to a club with 10 members. Four are selected for a match. Find the probability that both brothers are selected.

  • Very old man
    problem
    Favourite

    Very Old Man

    Age
    16 to 18
    Challenge level
    1 out of 3

    Is the age of this very old man statistically believable?

  • Stats statements
    problem
    Favourite

    Stats Statements

    Age
    16 to 18
    Challenge level
    1 out of 3

    Are these statistical statements sometimes, always or never true? Or it is impossible to say?

  • Rain or Shine
    problem
    Favourite

    Rain or Shine

    Age
    16 to 18
    Challenge level
    2 out of 3

    Predict future weather using the probability that tomorrow is wet given today is wet and the probability that tomorrow is wet given that today is dry.

  • Knock-out
    problem
    Favourite

    Knock-Out

    Age
    16 to 18
    Challenge level
    2 out of 3

    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?

  • Put Out
    problem
    Favourite

    Put Out

    Age
    16 to 18
    Challenge level
    3 out of 3

    After transferring balls back and forth between two bags the probability of selecting a green ball from bag 2 is 3/5. How many green balls were in bag 2 at the outset?

  • Limiting Probabilities
    problem
    Favourite

    Limiting Probabilities

    Age
    16 to 18
    Challenge level
    3 out of 3

    Given probabilities of taking paths in a graph from each node, use matrix multiplication to find the probability of going from one vertex to another in 2 stages, or 3, or 4 or even 100.