Question

[mittfull]

In how many different ways can a set of nine books be arranged on a shelf so that volumes one, two, and three are beside one another?

 

[Deleted member 4993]

In how many different ways can a set of nine books be arranged on a shelf so that volumes one, two, and three are beside one another?

Tie up volumes 1,2 and 3 - and count that as one book.

Now you have 7 books to arrange. How many ways can you arrange those?

How many ways can you arrange volumes 1,2 & 3?

Now think....