Question

Let ={a,b,c,d}. How many strings are there in 4?

Answer 1

Given:

Let ={a,b,c,d}.

To find:

Number of strings = ?

Solution:

According to the question,

The number of strings containing each of 4 letters exactly once will be:

= $4!$

= $4\times 3\times 2\times 1$

= $24$

Thus, the correct answer will be 24.