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    please help with this question

    A new housing development contains 100 properties of which 40 are semi-detached houses, 25 are detached houses, 20 are semi-detached bungalows and 15 are detached bungalows. a property is selected at random. Determine the probability that the property selected is:

    a. either detached or a bungalow or both
    i could do it if it were detached or a bungalow but 'or both' is confusing me.

    thanks
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    (Original post by Flint_09)
    please help with this question

    A new housing development contains 100 properties of which 40 are semi-detached houses, 25 are detached houses, 20 are semi-detached bungalows and 15 are detached bungalows. a property is selected at random. Determine the probability that the property selected is:

    a. either detached or a bungalow or both
    i could do it if it were detached or a bungalow but 'or both' is confusing me.

    thanks


    contains 100 properties of which 40 are semi-detached houses, 25 are detached houses, 20 are semi-detached bungalows and 15 are detached bungalows


    e: misread the question - don't do this! See below for proper solution.
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    It means either a detached house, a bungalow, or a detached bungalow. It isn't a well written question.

    Be careful not to count detached bungalows twice.
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    (Original post by M_E_X)


    contains 100 properties of which 40 are semi-detached houses, 25 are detached houses, 20 are semi-detached bungalows and 15 are detached bungalows



    Ok, so we have:

    40 semi-detached houses
    25 detached houses
    20 semi-detached bungalows
    15 detached bungalows


    The two in bold are relevant to our question. Obviously a house cannot be both a detached and semi-detached, so the number of houses which are both is zero, and we can ignore it.

    Can you finish the problem from here? Hope I've helped!
    i couldn't, sorry. it is not giving me the answer in the book, 0.60.
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    (Original post by Flint_09)
    i couldn't, sorry. it is not giving me the answer in the book, 0.60.
    EEP I misread the question - oops!

    "either detached or a bungalow or both"



    40 semi-detached houses
    25 detached houses
    20 semi-detached bungalows
    15 detached bungalows


    That's better. It's either a detached house, detached bungalow, or semi-detached bungalow.

    Get it now? The question tricked me
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    (Original post by M_E_X)
    EEP I misread the question - oops!

    "either detached or a bungalow or both"



    40 semi-detached houses
    25 detached houses
    20 semi-detached bungalows
    15 detached bungalows


    That's better. It's either a detached house, detached bungalow, or semi-detached bungalow.

    Get it now? The question tricked me
    thanks alot mate. you made it crystal clear now.
 
 
 
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