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VCE Stuff => VCE Mathematics => VCE Mathematics/Science/Technology => VCE Subjects + Help => VCE Mathematical Methods CAS => Topic started by: TrueTears on November 24, 2008, 02:59:36 pm

Title: probability Q
Post by: TrueTears on November 24, 2008, 02:59:36 pm: George is equally likely to choose any combination of the following fruits: strawberry, apple, watermelon, orange, raspberry and mango to make a fruit juice.
what is the probability he choose strawberry given he chooses 3 fruits.
Title: Re: probability Q
Post by: Flaming_Arrow on November 24, 2008, 03:03:49 pm: whats the answer?
Title: Re: probability Q
Post by: TrueTears on November 24, 2008, 03:11:04 pm: not sure this wasn't in a book it was a Q my teacher wrote on the board no answer. lol
Title: Re: probability Q
Post by: /0 on November 24, 2008, 05:26:39 pm: # ways of choosing strawberry along with 2 other fruits = ${5 \choose 2}$

# ways of choosing 3 fruits = ${6 \choose 3}$

$Pr( strawberry | \mbox{ 3 fruits}) = \frac{ \mbox{ways of choosing strawberry and choosing 3 fruits}}{ \mbox{ways of choosing 3 fruits}}= \frac{{5\choose 2}}{{6 \choose 3}} = \frac{1}{2}$ ?
Title: Re: probability Q
Post by: Flaming_Arrow on November 24, 2008, 05:35:16 pm: Quote from: DivideBy0 on November 24, 2008, 05:26:39 pm
# ways of choosing strawberry along with 2 other fruits = ${5 \choose 2}$

# ways of choosing 3 fruits = ${6 \choose 3}$

$Pr( strawberry | \mbox{ 3 fruits}) = \frac{ \mbox{ways of choosing strawberry and choosing 3 fruits}}{ \mbox{ways of choosing 3 fruits}}= \frac{{5\choose 2}}{{6 \choose 3}} = \frac{1}{2}$ ?

thats what i thought as well
Title: Re: probability Q
Post by: TrueTears on November 24, 2008, 05:36:33 pm: Quote from: Flaming_Arrow on November 24, 2008, 05:35:16 pm
Quote from: DivideBy0 on November 24, 2008, 05:26:39 pm
# ways of choosing strawberry along with 2 other fruits = ${5 \choose 2}$

# ways of choosing 3 fruits = ${6 \choose 3}$

$Pr( strawberry | \mbox{ 3 fruits}) = \frac{ \mbox{ways of choosing strawberry and choosing 3 fruits}}{ \mbox{ways of choosing 3 fruits}}= \frac{{5\choose 2}}{{6 \choose 3}} = \frac{1}{2}$ ?

thats what i thought as well
o yeah thanks thats right. Btw i flaming_arrow SAILOR MARS FTW LOLOLOL! flameeeee sniperrrrrr :P
Title: Re: probability Q
Post by: Flaming_Arrow on November 24, 2008, 05:45:16 pm: sailor mars ftw indeed.