SOLUTION: a red number cube and a white number cube are rolled.find the probability that the red number cube shows a 2, given that the sum showing on the two number cubes is less then or equ

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Question 227198: a red number cube and a white number cube are rolled.find the probability that the red number cube shows a 2, given that the sum showing on the two number cubes is less then or equal to 5
Answer by stanbon(75887) About Me  (Show Source):
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a red number cube and a white number cube are rolled.find the probability that the red number cube shows a 2, given that the sum showing on the two number cubes is less then or equal to 5
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Sketch the sample space for the two cubes.
You should end up with 36 sums running from 2 to 12
and having the form r+w (meaning red + white)
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Count the number of r+w sums where that are <=5
1+1=2
1+2=3
1+3=4
1+4=5
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2+1=3
2+2=4
2+3=5
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3+1=4
3+2=5
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4+1=5
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There are 10 such sums
3 of them have a red 2
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P(red 2 when sum <=5) 2/10 = 1/5
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Cheers,
Stan H.