Question

5 books (math, science, biology, chemistry, A&P) are to be arranged next to each ither on a shelf. In how many ways can they be arranged? Name two possible such arrangments. Show all work.

Answer 1

The first book can be placed in any of the 5 spaces. It will occupy 1 place which leaves us with 4 unoccupied spaces.

Second book can be placed in any of the 4 remaining spaces, leaving 3 unoccupied.

Third book can be placed in any of the 3 remaining places, with 2 remaining.

Fourth book can be placed in either of the 2 remaining places, leaving 1 for the final book.

So total number of ways in which 5 books can be placed is: 5*4*3*2*1 =5! = 120

or

We can use permutation nPr=

math, science, biology, chemistry, A&P

math, biology,science, chemistry, A&P

answered by: anonymous