How many ways can a dance instructor send 4 of her 11 students to a summer dance program? 7920 1980 720 330

Question

asked Jun 2, 2021 207k views

1 Answer

Hollance · Answer 1 · 2021-06-09T02:29:13+0000

Answer:

d) 330

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
$n_{C_(r) } = (n!)/((n-r)!r!)$

now simplification

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

=
(11X10X9X8X7!)/((7!)4X3X2X1)

after cancelling 7! and on simplification

=
(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