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This thread is just what the title says it is. It is all about Math. You can post math jokes(the jokes don't have to be good), math questions, what you like about Math, or even why you hate Math.
My math joke: Resistance is not futile. It is voltage divided by amps.
Are there bandaids in the electronics classroom? :P
That's impossible cuz pi has more than a million digits.
Ummm well I already read this whole math thread so I know that the answer is 0. And, I know 103 digits of Pi. 3.14159265358979323846264338327950288419716939937510582097494459230781640628620899862803482534211706798 I used to know more but I forgot about a dozen.
Interesting math thing of the day: Ulam's spiral. Look it up, it's pretty cool.
Okay... suppose you have three cards:
One black on both sides
One Red on both sides
On black on one side, red on the other.
Now, you close your eyes and mix up the cards. Then you randomly pick one.
It is black side up. What is the probability that the other side is red? Why?
Another question: Given that one side is black, what is the probability that you picked the red-black card? Why?
It is black side up. What is the probability that the other side is red? Why?
Another question: Given that one side is black, what is the probability that you picked the red-black card? Why?
Isn't that the same question?
Which leaves two choices, red-black or black-black. Meaning there is a 1/2 chance you got the red-black.
Lol, that's what i originally thought, i just thought the answer would be less obvious :b
I think #1 is 50% because it can't be red-red and if its the black-red it'll be red and if it's the black-black it'll be black.
I didn't see the answer if anyone posted it but I saw aknerd's above post, wouldn't it be the same for the second one?
It turns out the two questions don't have the same answer. Why?
Well, 1/3 is the correct answer for this first question. But I'm not too sure on your reasoning. I mean, asking what the chances the other side is red is the same thing as asking what the chances the card is the black red card.
The questions differ because the first one specifies that that the card is drawn black side up. And the second only specifies that there is a black side.
Well, 1/3 is the correct answer for this first question. But I'm not too sure on your reasoning. I mean, asking what the chances the other side is red is the same thing as asking what the chances the card is the black red card.
If the card is black side up, then you know it can only be one of two cardsâ"either the black-black card, or the black red card. However, it is less likely for the red-black card to be drawn black side up than for the black-black card. So this is how the probability goes:
For each card there's a 50/50 chance it was picked. For each card there's a 50/50 chance that the up-side (for explanation's sake let's say the up-side is black on the black-red card) will be drawn. So with the black-red card, of the 50% chance that it was picked, 100% of those outcomes result in the black side being up. With the red card that only happens 50% of the time it is picked. Therefore yes, it is 1/3. I'm kind of confusing myself as I say this but I believe the answer is 1/3. And I do sort of understand how to two questions are different. I'll think about this more and hopefully someone will come up with a good answer/explanation.
If the card is black side up, then you know it can only be one of two cardsâ�"either the black-black card, or the black red card. However, it is less likely for the red-black card to be drawn black side up than for the black-black card
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