Auto Generated Question

Back

1 . Let

k

and

n

be integers with

2 \leq k \leq n

and consider the set

S = {1, 2, \dots, n}

. What is the number of

k

-element subsets of

S

that do not contain 1 and do not contain 2?

(a)

(\binom{n - 1}{k - 1})

(b)

(\binom{n - 1}{k})

(c)

(\binom{n - 2}{k})

(d)

(\binom{n - 2}{k - 2})