this is the last one.. please help. thanks!


4. Twelve ships enter the St. Jhon

 

ttt

 

Off hand, I'd say that if your test's tomorrow it's a little late to be getting help on these.

Whatever.

a. 12!
b. 9! * 3! * 2!
c. 8! * 5!
d. 12! - (11! * 2!)

 

thanks so much! how did you get the solutions to b,c, and d? im going to have similar problems on my test tomorrow and it would be really helpful if you can just show me how you worked it out...

thanks again.

 

b. There are nine "groups" of ships: the Canadian ships form one group (1), each of the Portuguese ships is a group (2, 3, 4), the Icelandic ships form one group (5), the Greenlandic (?) ships each form a group (6, 7), the Bahamian ship is a group (8), and the American ship is a group (9): there are 9! ways to arrange the groups. For each such arrangement, there are 3! ways the Canadian ships can enter, and 2! ways the Icelandic ships can enter. Hence, 9! * 3! * 2!.

c. There are eight groups: 3 Portguese, 2 Greenlandic, 1 Bahamian, 1 American, and 1 Icelandic-Canadian (Iceladian? Canadandic?), so there are 8! ways the groups can come in; for each such arrangement, there are 5! ways the Iceladian / Canadandic ships can come in. Hence, 8! * 5!.

d. There are 12! ways for the ships to come in. If the American and Bahamian (Amerihamian?) ships are together, there are 11 groups and 11! * 2! ways to come in. If they're not together, that must be the remaining 12! - (11! * 2!) ways.

 

Just Magician doing what he does best. Danger, you're lucky you're getting help from a college math professor but you really should've learned this stuff beforehand.

 

thank you so much! this definately helped!

 

Damn

 

you're absolutely right.. thats why im stayin up tonight and payin for it.. its 130est and i dont plan on goin to bed anytime soon.


thanks again magician

 

You flatter me.

As I believe I mentioned in my initial response. Thanks for backing me up on this.