Question

Mrs. Jordan has a collection of 7 expensive dolls.
How many different ways.can she arrange 3 of them in a straight line for a photo?

Answer 1

Using the permutation formula, it is found that she can arrange 3 of them in a straight line for a photo in 210 ways.

Arrangements imply that the order is important, thus, the permutation formula is used to solve this question.

Permutation formula:

The number of possible permutations of x elements from a set of n elements is given by:

$P_{(n,x)} = \frac{n!}{(n-x)!}$

In this problem, she wants to arrange 3 dolls in a set of 7, thus:

$P_{(7,3)} = \frac{7!}{(7-3)!} = 210$

She can arrange 3 of them in a straight line for a photo in 210 ways.

A similar problem is given at https://brainly.com/question/24245547