问一道英文数学题目（美国高中水平的）In a survey of 63 people,23 people subscribed to magazine A,21 people subscribed to magazine B,and 17 subscribed to magazine C.For any two of the magazaines,4 people subscribed to both magazines but not to the thrid magazine.If 5 people in the survey did not subscribe to any of three magazines,how many people subscribed to all three magazines?怎么我一直做都是负数呢?
问题描述：
问一道英文数学题目（美国高中水平的）
In a survey of 63 people,23 people subscribed to magazine A,21 people subscribed to magazine B,and 17 subscribed to magazine C.For any two of the magazaines,4 people subscribed to both magazines but not to the thrid magazine.If 5 people in the survey did not subscribe to any of three magazines,how many people subscribed to all three magazines?
怎么我一直做都是负数呢?
答