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    Right, I have S1 tomorrow and I've been doing a past paper...yet I can't quite understand this one, I have the answer from the mark scheme.

    P(A) = 0.65 P(AUB)=0.93

    Evaluate P(B) given that:
    a) A & B are independent.

    So I'd do P(AUB)=P(A)+P(B)-P(A)P(B)
    then put in the figures...
    P(AUB)=0.65+P(B)-0.65(PB)

    And this is where I get confused...
    The rest of the mark scheme has:
    0.35P(B) = 0.28
    P(B) = 0.28

    I don't understand where the 0.35P(B) has come from!
    Any help is appreciated, thanks!
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    Anyone?
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    0.65 + 0.28 = 0.93

    The question has used P(AUB) = P(A) + P(B)
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    sorry i don't actually think that what you were asking.. i'll have another look
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    sorry i don't actually think that what you were asking.. i'll have another look
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    (Original post by danielharris627)

    So I'd do P(AUB)=P(A)+P(B)-P(A)P(B)
    then put in the figures...
    P(AUB)=0.65+P(B)-0.65(PB)

    And this is where I get confused...
    The rest of the mark scheme has:
    0.35P(B) = 0.28
    P(B) = 0.28

    I don't understand where the 0.35P(B) has come from!
    Any help is appreciated, thanks!
    You have P(B)-0.65P(B) in your solution. 1-0.65=0.35 hence the 0.35P(B)

    I assume the last line should be P(B) = 0.28/0.35 = 0.8
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    yeah, i agree,

    i get how they find 0.35B=0.28
    but not sure how they then deduce that B=0.35

    sorry :/
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    (Original post by tiny hobbit)
    You have P(B)-0.65P(B) in your solution. 1-0.65=0.35 hence the 0.35P(B)

    I assume the last line should be P(B) = 0.28/0.35 = 0.8
    yeah.. answer is probably wrong
 
 
 
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