There are 2*5! = 240 ways.
it depends on the shelf of course
using the Dewey decimal system
Slowly and methodically, I arranged the books on the shelf.
because of gravity. i think
120. You do 5*4*3*2*1=120. you multiply the number that you are given for example how many times can books 3 be arranged on a shelf you multiply 3*2*1=6 that is your answer
The number of permutations of five things taken five at a time is five factorial, or 120.
The answer depends on how many books on each subject there are.