SOLUTION: Any help would be so appreciated. Thank you. 10 books are to be arranged on a shelf. 4 of the books have red covers, 3 have green covers, and another 3 have gray covers. In how

Algebra ->  Permutations -> SOLUTION: Any help would be so appreciated. Thank you. 10 books are to be arranged on a shelf. 4 of the books have red covers, 3 have green covers, and another 3 have gray covers. In how       Log On


   



Question 488859: Any help would be so appreciated. Thank you.
10 books are to be arranged on a shelf. 4 of the books have red covers, 3 have green covers, and another 3 have gray covers. In how many ways can the books be arranged on a shelf if books of the same color must be arranged together?

Answer by josmiceli(19441) About Me  (Show Source):
You can put this solution on YOUR website!
Without ordering the books of the same color,
here is the possible ways to order books of different colors:
(1) [ 4 red ][ 3 green ][ 3 gray ]
(2) [ 4 red ][ 3 gray ][ 3 green ]
----------------------
(3) [ 3 green ][ 4 red ][ 3 gray ]
(4) [ 3 gray ][ 4 red ][ 3 green ]
----------------------
(5) [ 3 gray ][ 3 green ][ 4 red ]
(6) [ 3 green ][ 3 gray ][ 4 red ]
----------------------
So, there are 6 different ways to order
books of different colors (1) through (6)
The possible ways that books of the same color
can be ordered for each of the (6) is:
+4%21+%2A+3%21+%2A+3%21+=+24%2A6%2A6+
+24%2A6%2A6+=+864+
----------------------
You can have (1) OR (2) OR (3) OR (4) OR (5) OR (6)
So, the choices for different color orderings get added
+864+%2B+864+%2B+864+%2B+864+%2B+864+%2B+864+=+5184+
There are 5184 possible arrangements of the books
You should get other opinions, too.