# Quod Erat Demonstrandum

## 2009/02/03

### 出現 A 先於 B 的機會

$\frac{3}{36} \div (\frac{3}{36} + \frac{4}{36}) = \frac{3}{7}$

$P(C) = P(A)P(C | A) + P(B)P(C | B) + P(D)P(C | D)$

$P(C) = P(A)\times 1 + P(B)\times 0 + P(D)P(C)$
$P(C) = \frac{P(A)}{1 - P(D)} = \frac{P(A)}{P(A \cup B)}$

$P(C) = \frac{P(A)}{P(A) + P(B) - P(A \cap B)}$ – – – – – – (*)

$P(C) = \frac{P(A)}{P(A) + P(B)}$

## 3 則迴響 »

1. I have a question, how can you make the pages such that it only shows the summary or the first few sentences of each post? (i.e. you have a little (more) button for me to click into this post)

迴響 由 koopakoo — 2009/02/05 @ 12:31 下午 | 回覆

2. Above the edit window, you may see a tool bar. Click the button “more" on the bar, then the tag < !–more– > will appear in you content of editing , and the content after the tag < !–more– > will be hidden just showing (more) in your post. But the effect will not be seen during editing, it works only after publishing your post. Try!

迴響 由 johnmayhk — 2009/02/05 @ 2:01 下午 | 回覆

3. It worked! Thank you very much.

迴響 由 koopakoo — 2009/02/05 @ 8:14 下午 | 回覆