Question

How many ways can 5 different books be arranged on a shelf?

Answer 1

Answer:

120

Explanation:

Assuming that the books are distinguishable:

There are 5 choices for the left-most book.

For each of these choices there are 4 choices for the second book from the left;

giving 5×4=20 choices for the first two books on the left.

Having chosen the first 2 books there are 3choices for the third book from the left;

giving 5×4×3=60 choices for the first three books on the left.

Having chosen the first 3 books there are 2choices for the fourth book from the left;

giving 5×4×3×2=120 choices for the first four books on the left.

This only leaves 1 choice (not really a "choice") for the fifth book;

giving 5×4×3×2×1=120 choices for arranging the books (from left to right).

Answer 2

Answer:

Answer is :- 120/-

Step-by-step explanation:

I'm giving up a formula which will provide you always a correct answer for such questions:-

 = please check image file attached