A local dry cleaner interviewed 15 candidates for the positions of cashier, washer, and delivery driver. How many ways can
they fill the 3 positions?
18
45
455
2,730

Respuesta :

Answer:

D. 2730

Step-by-step explanation:

I just had this question on FLVS yesterday.
you use factorials for this:

15!/12!

15*14*13*12!/12!

15*14*13

2730

Number of ways in which 3 positions can be filled are 2730.

What is permutation and combinations?

The number of ways in which objects from a set may be selected, generally without replacements, to form subsets. This selection of subset is called permutation when order of selection is a factor.

If n things taken r at a time and n!  = n × (n-1) × (n-2) × (n-3)..........3 × 2 × 1

⇒Permutation,

                              [tex]P(n,r) =\frac{n!}{(n-r)!}[/tex]

Now it is given that number of candidates, n = 15

and number of position, r = 3

Hence number of ways positions can be filled-

                           [tex]P(n,r) =\frac{15!}{(15-3)!}[/tex]

⇒                         [tex]P(15,3) =\frac{15!}{12!}[/tex]

⇒                         P(15,3) =  (15 × 14 × 13)12!/12!

⇒                         P(15,3) =  (15 × 14 × 13)

⇒                         P(15,3) =  2730

∴ Number of ways in which 3 positions can be filled are 2730.

More about Permutation :

https://brainly.com/question/27951291

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