2) At a chess tourment with 12 players, each player played exactly 1 game with all but one of the other players. how many games were played at the tourment?ans:60
3) how many ways can 6 students be seated in a row if 2 particular students must be seated next to each other? ans:240
4) how many positive even integers less than 1000 can be formed from the digits 0,1,2,3,4,5?ans:107
5) how many ways can 6 students be seated in a row if 2 particular ctudents are to be separated? ans: 480
6) I invite 4 couples to dinner and seat them at a round table. how many ways can i arrange them if emn and women sit alternately? ans: 144
7) how many different ways can you answer a 7 question multiple 3 choice exam if you know no two consecutive answers are the same? ans:192
Thanks!
更新1:
will you please explain why?? thank you!