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Ginger has a box of 6 marbles. There are 2 red marbles, 3 blue marbles, and 1 green marble. What is the probability of Ginger randomly drawing 1 blue marble and then 1 red marble?
Total marbles = 6.
A = drawing 1 blue marble.
B = drawing 1 red marble.
P(A and B) = P(A) • P(B)
P(A and B) = 3/6 • 2/6
P(A and B) = 6/36
P(A and B) = 1/6
You say?
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Should be 3/6 * 2/5, since there's no replacement, right?
"The most incomprehensible thing about the world is that it is comprehensible." -Albert Einstein.
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Should be 3/6 * 2/5, since there's no replacement, right?
Now I am lost.
Without replacement means we put item back in and independent events.
Yes?
With replacement means we do not put item back in and this dependent events.
Yes?
If not, can you please clear this up for me once and for all?
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Other way around: with replacement means putting the item back in, thereby replacing it, yielding independent events.
Without replacement means not putting the item back in, i.e. not replacing it, yielding dependent events.
"The most incomprehensible thing about the world is that it is comprehensible." -Albert Einstein.
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Other way around: with replacement means putting the item back in, thereby replacing it, yielding independent events.
Without replacement means not putting the item back in, i.e. not replacing it, yielding dependent events.
Yeah, it's all clear now but I must put myself to the test by answering a few more questions just to be sure.
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Keep_Relentless wrote:Other way around: with replacement means putting the item back in, thereby replacing it, yielding independent events.
Without replacement means not putting the item back in, i.e. not replacing it, yielding dependent events.
Yeah, it's all clear now but I must put myself to the test by answering a few more questions just to be sure.
I think this is called conditional probability, when we don't put the first marble back in (so the probability of the second pick is conditional on the first).
Prioritise. Persevere. No pain, no gain.
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mathxyz wrote:Keep_Relentless wrote:Other way around: with replacement means putting the item back in, thereby replacing it, yielding independent events.
Without replacement means not putting the item back in, i.e. not replacing it, yielding dependent events.
Yeah, it's all clear now but I must put myself to the test by answering a few more questions just to be sure.
I think this is called conditional probability, when we don't put the first marble back in (so the probability of the second pick is conditional on the first).
In conditional probability, there are two cases:
1. We don't put items back in----->without replacement.
2. We put items back in---->with replacement.
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