别讨论鸡了, 今天改鸭子话题

[shw019]

就是4只鸭子被扔进一个圆形池塘，求他们四个同时在一个半圆的概率。

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我怎么觉得图片里的是四只小鸡呢?

 

[fierysteed]

I start with two
It's 100 on one side

this is correct

Then I throw the third one it's 50 to fall on either side.

this is wrong.
actually, in any case, it's ALWAYS larger than 50%.
e.g if first two 10 , the third one has 350/360 to be valid
if first two 30, the third one has 330/360 to be valid
if first two 50, the third one has 310/360 to be valid
if first two 70, the third one has 290/360 to be valid
if first two 90, the third one has 270/360 to be valid
if first two 120, the third one has 240/360 to be valid
.........

 

[卡城西北]

我想了一个比方
一张饼 切了一刀之后 饼的面积不变
咬了一口 面积减少 影响计算

俗。一般都分黄金，黄金分割听说过吧？谁分饼啊。

 

[Reminiscence]

我怎么觉得图片里的是四只小鸡呢?

一字之差，导致卡西北秒发了四贴。

 

[Reminiscence]

this is correct

this is wrong.
actually, in any case, it's ALWAYS larger than 50%.
e.g if first two 10 , the third one has 350/360 to be valid
if first two 30, the third one has 330/360 to be valid
if first two 50, the third one has 310/360 to be valid
if first two 70, the third one has 290/360 to be valid
if first two 90, the third one has 270/360 to be valid
if first two 120, the third one has 240/360 to be valid
.........

现在我信你是曾经的高考状元了。

 

[sabre]

this is correct

this is wrong.
actually, in any case, it's ALWAYS larger than 50%.
e.g if first two 10 , the third one has 350/360 to be valid
if first two 30, the third one has 330/360 to be valid
if first two 50, the third one has 310/360 to be valid
if first two 70, the third one has 290/360 to be valid
if first two 90, the third one has 270/360 to be valid
if first two 120, the third one has 240/360 to be valid
.........

容我慢慢想
目前接受不了

 

[sabre]

this is correct

this is wrong.
actually, in any case, it's ALWAYS larger than 50%.
e.g if first two 10 , the third one has 350/360 to be valid
if first two 30, the third one has 330/360 to be valid
if first two 50, the third one has 310/360 to be valid
if first two 70, the third one has 290/360 to be valid
if first two 90, the third one has 270/360 to be valid
if first two 120, the third one has 240/360 to be valid
.........

我开始接受你的理论了

两只鸭子的时候 线不是画死的
根据第三只落点 画线 比二分之一大

有意思

 

[fierysteed]

我开始接受你的理论了

两只鸭子的时候 线不是画死的
根据第三只落点 画线 比二分之一大

有意思

Now I am kind of remember the math learned from university

for the expected value of max angle of 3 ducks.

set 180 as 1.

x*x +(1-x)((1+x)/2) -> 积分 from 0 to 1
get 2/3,

which is 120.