F.6 combination－fksnlix的部落格

標題:

F.6 combination

發問:

8) A committee of 4 is selected from a group of 8 boys and 6 girls. If the committee must have at least one girl, in how many ways can the committee be selected?有冇式呀我唔識,, 9) In how many ways can 9 students be divided into 3 groups of 3 if no regard is paid to the order of the group?式? 更新: 第9題answer 係280but 第8題對了answer~thx~!

最佳解答:

8) A committee of 4 is selected from a group of 8 boys and 6 girls. If the committee must have at least one girl, in how many ways can the committee be selected?有冇式呀我唔識,, 1 girl, 3 boys, (6C1)(8C3) = 336 2 girls, 2 boys, (6C2)(8C2) =420 3 girls, 1 boys, (6C3)(8C1) =160 4 girls, 0 boys, (6C4)(8C0) =15 336 + 420 + 160 + 15 = 931 9) In how many ways can 9 students be divided into 3 groups of 3 if no regard is paid to the order of the group?式? (9C3)(6C3) = 1680