求助11月jj的203题

看了半天也不懂，完全绕进去了……感觉像文字游戏啊……求助nn们

203. 78% student was graduated from the school in 1980. 89% students graduated from the school in 1980. 问满足两个条件的学生比例。（为nonpanicfan版本的第13题）

这种题目的经典解释是：肉包子中a%是有摺的，有摺包子中b%是肉包子，实际上隐含的关系就是肉包子有摺的=有摺的肉包子，都是同一批包子（1980年毕业生的数目是一样的）..忘记是哪位NN在哪个月提出来的..拜服一下
                            

变体题目（或者说本身就是原题）：The sentence "students was graduated from high school" is accepted by 89% of the students, and the sentence   ''students graduated from high school '' is accepted by 78% of the students. 问两个同时被accept的概率。70%

疑问：1. 78% 对应的100%的总体人群是谁啊？

这种题目的经典解释是：肉包子中a%是有摺的，有摺包子中b%是肉包子，实际上隐含的关系就是肉包子有摺的=有摺的肉包子，都是同一批包子（1980年毕业生的数目是一样的）..忘记是哪位NN在哪个月提出来的..拜服一下
                

变体题目（或者说本身就是原题）：The sentence "students was graduated from high school" is accepted by 89% of the students, and the sentence   ''students graduated from high school '' is accepted by 78% of the students. 问两个同时被accept的概率。70%

疑问：1. 78% 对应的100%的总体人群是谁啊？

            2. 89%对应的100%的总体人群是谁啊？

            3.最后问的满足两个条件是哪两个条件？这个问题的100%的总体人群又是谁啊？