Four married couples have bought 8 seats in the same row for a concert. In how many different ways can they be seated
(a) With no restrictions?
(b) If each couple is to sit together?
(c) If all the men sit together to the right of all the women?
10.
Find the number of ways that 6 teachers can be assigned to 4 sections of an introductory psychology course if no teacher is assigned to more than one section and every section should have one and only one teacher.
11.
Nine people are going on a skiing trip in 3 cars that holds 2, 4, and 5 passengers, respectively. In how many ways is it possible to transport the 9 people to the ski lodge, using all cars?
更新1:
9b) 我用左8!/(2!2!2!2!)做點解唔啱既... 9c) 我用(1/2)*(8!/4!4!)做...同埋我想問題目寫左men sit to the "right" of women...咁解題時點樣考慮"right"呢樣野?
