Question

How many ways can a dance instructor send 4 of her 11 students to a summer dance program?

Answer 1

Answer:

d) 330

Step-by-step explanation:

The number of ways can a dance instructor send 4 of her 11 students to summer dance program is  C(11 , 4)

That is $11_{C_{4} }$ ways

by using formula $n_{C_{r} } = \frac{n!}{(n-r)!r!}$

now simplification

$11_{C_{4} } = \frac{11!}{(11-4)!4!}$

      = $\frac{11X10X9X8X7!}{(7!)4X3X2X1}$

after cancelling 7! and on simplification

   = $\frac{11X10X9X8}{4X3X2X1}$

after cancellation we get 330 ways

The number of ways can a dance instructor send 4 of her 11 students to summer dance program is 330