A real estate agent is showing homes to a prospective buyer. There are 10 homes in the desired price range listed in the area. The buyer wants to visit only 3 of them. a. In how many ways could the 3 homes be chosen if the order of visiting is considered? b. In how many ways could the 3 homes be chosen if the order of visiting is not important?

Respuesta :

There are 720 ways that the 3 homes could be chosen if the order of visiting is considered. There are 120 ways that the 3 homes could be chosen if the order of visiting is not important.

What is permutation?

A permutation is the arrangement or ordering of a finite set of an element.

From the information given:

If there are  10 homes in the desired price range listed in the area:

Then:

  • n = 10 and r = 3

So, the number of ways of choosing 3 out of 10 (without replacement) and arranging is:

[tex]\mathbf{^nP_r= \dfrac{n!}{(n-r)!}}[/tex]

[tex]\mathbf{^nP_r= \dfrac{10!}{(10-3)!}}[/tex]

[tex]\mathbf{^nP_r= \dfrac{10\times 9\times 8 \times 7!}{(7)!}}[/tex]

= 720 ways

Now, the number of ways of choosing 3 out of 10 if the order of visiting is not important is the combination of the elements and it can be computed as:

[tex]\mathbf{^nC_r= \dfrac{n!}{(n-r)!r!}}[/tex]

[tex]\mathbf{^{10}C_3= \dfrac{10!}{(10-3)!3!}}[/tex]

[tex]\mathbf{\implies \dfrac{10\times 8\times 9 \times 7!}{(7)! \times 3\times 2}}[/tex]

[tex]\mathbf{\implies \dfrac{10\times 8\times 9}{6}}[/tex]

= 120 ways

Learn more about permutation and combination here:
https://brainly.com/question/11732255

#SPJ1