I have 7 different geography textbooks and 4 different chemistry textbooks. In how many ways can I line the 11 textbooks on a bookshelf if a chemistry textbook must be in the middle and there must be a geography textbook at each end?
+130071 I'm not great at these counting problems, but here is my best attempt
We have 4 ways to choose the chemistry book that goes in the middle
And we have 7 ways to choose the geography book that goes first and 6 ways to choose the other geography book that goes last
And we have (3 + 5) = 8! ways to arrange the other books
So....the total arrangements = 4 * 7 * 6 * 8! = 6,773,760 arrangements
+118690 I have 7 different geography textbooks and 4 different chemistry textbooks. In how many ways can I line the 11 textbooks on a bookshelf if a chemistry textbook must be in the middle and there must be a geography textbook at each end?
G ?? C ?? G 4chem and 7geog
7*6*4* ..... So no I have 8 books left that can go anyremaing place
7*6*4*8! = 6773760 Our answers should be the same Chris. I used the web2 calc, I think it was imputed correctly.
Melody, thank you for the correct answer!
CPhill, you could learn a thing or two from Melody about getting the right answer!
+118690
You could learn a thing or 2 about manners guest!
CPhil's answer was spot on. A typo at the end is absolutely nothing.
You should be assamed of yourself talking to CPhill like that after he went out of his way to answer YOUR question!
