BBC GCSE Question

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  • BBC GCSE Question
  • pingu66
    Member

    Not sure if I am losing it but this seems like nonsense.

    BBC Linky

    MATHS: A pet shop had 40 rabbits.
    22 were male.
    The others were female.
    The shop sold 10 of the rabbits.
    The probability that a rabbit picked at random is male is now 1/2 (0.5).
    How many female rabbits were sold?

    Choices 3, 4 or 5.

    BBC explanation!!!!!

    It’s 3. There were 18 rabbits (40-22=18) originally. To have a 1/2 (one-in-two) chance of picking out a male after 10 were sold, there would need to be 15 of each sex – so 18-15=3.

    Premier Icon wors
    Subscriber

    Did you fail English too….. 😉

    I make it 3 female rabbits sold

    Premier Icon Cougar
    Subscriber

    There are (40-10)=30 rabbits post-sale.

    There is now a 50:50 chance of one being male, ie an equal number. Ergo, there are now 15 male and 15 female.

    There was originally (40-22)=18 female rabbits. There is now 15 female rabbits. 18-15=3.

    Capiche?

    pingu66
    Member

    Works for me now, completely thrown by the first statement of the answer that there were 18 rabbits originally!

    Big thanks, makes sense.

    @wors stealthy edit – long time since I was at school and rely too much on spell checker.

    Premier Icon convert
    Subscriber

    Good job you don’t have to sit one those ‘oh so easy’ GCSEs then. That’s not tricky in the big scheme of things.

    pingu66
    Member

    I genuinely did OK on the others with a lucky guess on one. But I don’t think the exams are easy! Puts the young people under pressure and expectation.

    Maybe not that tricky but if you get to over thinking then it is.

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