Answer:
720 ways
Explanation:
At first their are six books, that means that there are six different positions to put them. The first book to be placed would have 6 position, when the first book is placed, to place the second book there would be 5 position since one position has been used by the first book. After placing the second book, to place the third book there would 4 available position, and it follows this manner i.e for the fourth book 3 available position, for the fifth book 2 available position and for the sixth book, one available position.
Therefore the number of ways to arrange the books on the shelf from left to right = 6 × 5 × 4 × 3 × 2 × 1 = 6! = 720 ways