Question

A series of math books has 7 volumes. In how many ways can they be arranged on a shelf so that they are not in order?

Answer 1

Answer I got was 7!-1 but can it be 7! -2?

Answer 2

what does 'in order' signify? does it mean no 2 volumes are next to each other?

Answer 3

if there is only one way for them to be in order .... assuming left to right

then 7!-1 is correct

Answer 4

they have to be in order, so like 1,2,3... but i was also thinking can it not start from 7,6,5...

Answer 5

if 'in order' is not defined for you, then you should define it beforehand and work the solution according to your definition

Answer 6

okay thanks. i'll define it.

Answer 7

:) good luck