如果三个人,约翰,威尔玛和保罗拒绝坐连续三个座位,
需要8个人坐在一排椅子上.约翰,威尔玛和保罗不想彼此相邻坐.为了找到可能的座位安排的总数,我们从8开始! (八个因数,即8 × 7 × 6 × 5 × 4 × 3 × 2 × 1).为了找到约翰,威尔玛和保罗相邻坐的座位安排,我们把他们当作一个群体,首先安排6个 (JWP和其他5个),然后把约翰,威尔玛和保罗安排在那个群体内.这给我们6! × 3! (六个因数乘以三个因数).所以为了找到可接受的座位安排的数量,我们从可能的座位安排的总数中减去约翰,威尔玛和保罗坐的次数: 8! - 6 × 3 × 6 × 7 × 6 × 6 × 7 × 6 × 6 × 7 × 6 × 6 × 7 × 8 × 6 × 6 × 6 × 7 × 6 × 6 × 7 × 6 × 6 × 7 × 6 × 6 × 7 × 6 × 7 × 8 × 7 × 6 × 6 × 6 × 7 × 6 × 6 × 7 × 6 × 7 × 7 × 6 × 7 × 7 × 8 × 7 × 7 × 6 × 6 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 8 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 8 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 8 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 8 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 8 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 8 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 × 7 ×