Question

Find the number of permutations of five letters A, B, C, D, E taken 4 at a time in which
A is present.
step by step explanation please​

Answer 1

Answer:

Find the number of permutations of five letters A, B, C, D, E taken 4 at a time in whichFind the number of permutations of five letters A, B, C, D, E taken 4 at a time in which

Step-by-step explanation:

Answer 2

We need to recall the following definitions to solve the permutation.

• The permutation is a way of arranging the objects in a definite order.
• Formula : $P(n,r)=\frac{n!}{(n-r)!}$

This problem is about permutation.

Given:

Letters are: A, B, C, D, and E

We have to arrange $4$ letters in which A is always present.

Letter A occurs at any position in $4$ ways.

For other $3$ positions, the number of ways is $^4C_3$.

Hence, the number of permutations is

$=4*^4C_3$

$=4*\frac{4!}{(4-3)!}$

$=96$