web2.0calc
 
+0  
 

 need help

0
16
1
avatar+817 

I have $4$ different mathematics textbooks and $3$ different psychology textbooks. In how many ways can I place the $7$ textbooks on a bookshelf, in a row, if there must be a mathematics textbook exactly in the middle, and all the psychology textbooks are together?

 Dec 14, 2023

1+0 Answers

 #1
avatar+129849 
+1

The psychology tetboooks can occupy  positions 1 - 3  or 5 - 7=   2 arrangements

And wthin these, they can be arranged in 3! = 6 ways

The math textbooks can then be arranged in 4! = 24 ways

 

So

 

2 * 6 * 24  =   

 

288 arrangements

 

cool cool cool

 Dec 14, 2023

2 Online Users

Top Users

avatar+37153 ElectricPavlov
avatar+33659 Alan moderator
avatar+14997 asinus moderator
avatar+9673 MaxWong
avatar+3146 admin administrator
avatar+2490 GingerAle
avatar+1895 NotThatSmart
avatar+1839 ABJeIIy
avatar+1768 bader
avatar+1533 parmen
avatar+1439 kittykat

Sticky Topics