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Math Help - I need some help with this probability question

  1. #1
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    I need some help with this probability question

    Ok this question been giving me problems and I've got it wrong 2 times already. It says the urn contains 40 marbles: 12 were white, 18 were red, and 10 were blue. One marble was drawn and then put back. Then a second marble was drawn. What is the probability that both marbles were blue? I looked in my text book and tried to go off what was in there. I came up with 10/40 reduced to 1/4 but that wasn't right if someone can help and let me know were I'm going wrong I'd gladly appreciate it. thanks
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  2. #2
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    \frac{1}{4} only applies for one marble being drawn.

    as you are looking two marbles being drawn with replacement maybe \frac{1}{4}\times \frac{1}{4} could be a better answer?
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  3. #3
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    thank's but I'm still a little confused.
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  4. #4
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    \frac{1}{4} only applies for one marble being drawn.

    as you are looking two marbles being drawn with replacement maybe \frac{1}{4} for the first marble and then  \times \frac{1}{4} for the second marble.

    \frac{1}{4}\times \frac{1}{4} = \dots
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  5. #5
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    thanks for all your help.
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