Assuming they are all right side up and spine out, there would be 40,320 different ways of arranging them.
Consider: There are 8 choices for the 1st book, 7 for the 2nd, 6 for the 3rd, 5 for the 4th, 4 for the 5th, 3 for the 6th, 2 for the 7th and 1 for the 8th. Multiplying these numbers out:
8 x 7 x 6 x 5 x 4 x 3 x 2 x 1 = 40,320. More than you thought?
The mathematical name for this is called finding the factorial of a number!
It is written n! ( n followed by an explanation point) -
If the books have to be the correct way up and spine outwards: 7! ways =7x6x5x4x3x2x1 =5040 ways. If the books can be any way in (upside down, spine inward, etc.): (7!x4^7) ways =7x4x6x4x5x4x4x4x3x4x2x4x1x4 =82,575,360 ways
it depends on the shelf of course
In how many distinct ways can the letters of the word MEDDLES be arranged?
The answer is 7!/5! = 42 ways.
Using the binomial coefficient and the 'choose' function, 10 books can be arranged 10! = 10 x 9 x 8 x 7 x 6 x 5 x 4 x 3 x 2 x 1 = 3628800 different ways.
7654321 = 7! = 5,040
If the books have to be the correct way up and spine outwards: 7! ways =7x6x5x4x3x2x1 =5040 ways. If the books can be any way in (upside down, spine inward, etc.): (7!x4^7) ways =7x4x6x4x5x4x4x4x3x4x2x4x1x4 =82,575,360 ways
81
There are 2*5! = 240 ways.
The answer depends on how many books on each subject there are.
there are 220 combinations of arranging 12 books chosing 3
it depends on the shelf of course
The number of ways that 15 books can be arranged on a shelf is the same as the number of permutations of 15 things taken 15 at a time. This is 15 factorial, or 15!, and is 1,307,674,368,000.
how many ways can 8 letters be arranged
Five numbers can be arranged in 5! = 120 ways.
9 x 8 x 7 x 6 x 5
4! = 24, they can be arranged in 24 different ways