Twelve students ask to visit a college admissions counselor. The counselor can meet with one student at a time. in how many ways can seven time slots be assigned?

Respuesta :

If we put all the seven slots and we caculate like this:

12*11*10*9*8*7*6
Then the result will be 3,991,680

I hope this can help you 

Answer:

792

Step-by-step explanation:

Given : Twelve students ask to visit a college admissions counselor. The counselor can meet with one student at a time.

To Find:In how many ways can seven time slots be assigned?  

Solution:

Total number of students = 12

No. of slots = 7

Counselor can meet 1 student at one time slot.

So, to find the number of ways in which  seven time slots can be assigned we will use combination:

Formula : [tex]^nC_r=\frac{n!}{r!(n-r)!}[/tex]

n = 12

r = 7

Substitute the given values :

[tex]^{12}C_7=\frac{12!}{7!(12-7)!}[/tex]

[tex]^{12}C_7=\frac{12 \times 11\times 10 \times 9\times 8\times 7! }{7!(5)!}[/tex]

[tex]^{12}C_7=\frac{12 \times 11\times 10 \times 9\times 8}{5 \times 4\times3\times2\times1}[/tex]

[tex]^{12}C_7=792[/tex]

Thus there are 792 ways in which seven time slots can be assigned.