So you finally realized that "应该充份说明新用户是对的了。"? (Or didn't your?)
And now you accuse others of not 'using the proper syntax' and thereby, wasting such precious 'breath' of yours? Should you at least appologize for being rude? That will be much more difficult than calling others 'Moron', isn't it?
and a FSA (the highest title) in Actuarial Science. Here was my message and his answer:www.ddhw.com
Hi,
Merry Christmas and Happy New Year to you and your family.
Could explain to me the difference between these two probabilities:
1. A man has two children. One of them is a boy. What's the probability that the other one is a boy? 2. A man has a boy. He will have another born in the future. What's the probability that the other one is a boy?
He replied right away:
1. P = 1/3 (BB, BG, GB) 2. P = 1/2 (BB, BG)
To a professional, there is not doubt in his mine about the first question.
1. A man has two children. One of them is a boy. What's the probability that the other one is a boy? 2. A man has a boy. He will have another born in the future. What's the probability that the other one is a boy? www.ddhw.com
If the second child will be born in the future, the child has 50% being boy or girl (as a coin). The question here is about the second child who was born already. Some people think it is different, which I do not agree with. www.ddhw.com
BTW, stupid is offensive. Nobody is right all the time. Let's focus on the problem and not use colorful words.www.ddhw.com
Go ask a statistics professor in a college. The two questions looked different, but they have the same answer.www.ddhw.com
A common mistake for students who learn probabilty theory: Instantiate instances based on the condition given, then calculate.
Rather, you should instantiate all instances first, then determine the rate by conditions.
Therefore, your first question, you should have 4 instances rather than 3, so that it should be 50% rather thahn 1/3, don't be fooled by the condition "one of then is a boy".
Anyway, I don't know why I bother tell you this. Please just go to ask a stat professor.
or not does not matter. The probability of the sex of the second is the same. The second analysis in your argument is the only right analysis. I don't understand how do you get the first analysis. Your first analysis is just wrong.
The following problems have the same answer:
1. I have two kids, the first is a boy, what is the probability of the second one is a boy?
2. I have two kids, what is the probability of the second one is a boy?
Yes, the answer to question one is definitely wrong. The author was arguing that the chances (or probability) of it being a girl is 2/3. However, that statement is wrong. It was based on the assumption that:
BG 1/3
GB 1/3
BB 1/3
However, if we are to work it out that way, it should be:
B1 G1 1/4
G1 B1 1/4
B1 B2 1/4
B2 B1 1/4www.ddhw.com
As stated by a previous poster, the BB combination should be counted twice. As such, it will end up that there is a 50/50 chance of it being a Girl or Boy. www.ddhw.com
So teh conclusion is: The guy should have his pay deducted by 10000USD per month!!!!
Yes, the answer to question one is definitely wrong. The author was arguing that the chances (or probability) of it being a girl is 2/3. However, that statement is wrong. It was based on the assumption that:
BG 1/3
GB 1/3
BB 1/3
However, if we are to work it out that way, it should be:
B1 G1 1/4
G1 B1 1/4www.ddhw.com
B1 B2 1/4
B2 B1 1/4
As stated by a previous poster, the BB combination should be counted twice. As such, it will end up that there is a 50/50 chance of it being a Girl or Boy.
So teh conclusion is: The guy should have his pay deducted by 10000USD per month!!!!