来自《耶鲁大学开放课程：金融市场 第2集 第2集》

• 
  
  Ideally, life insurance is insuring people--
  理想状态下 人寿保险
• 
  
  or fire insurance is insuring people--
  或者是火灾险
• 
  
  against independent events,
  承保的对象都是独立事件
• 
  
  so it's not the fire of London.
  伦敦大火的例子不在讨论范围
• 
  
  It's the problem that sometimes
  有时候会出现这种问题
• 
  
  people knock over an oil lamp in their home
  一个人把自己家里的油灯弄翻了
• 
  
  and they burn their own house down.
  然后把自己的房子点着了
• 
  
  It's not going to burn any other houses down
  由于火灾是独立事件
• 
  
  since it's just completely independent of anything else.
  他的房子着火了并不会烧毁别人的房子
• 
  
  So, the probability that the whole
  在这样的假设下 整个城市都被烧掉的概率
• 
  
  city burns down is infinitesimally small, right?
  是非常非常小的
• 
  
  This will generalize to probability of A and B and C
  简单的说 A和B和C同时发生的概率