Question

A tray contains 12 chocolate cookies and 16 oatmeal raisin cookies. How many ways can a child select 4 cookies that include at least 1 chocolate chip cookie? I think its Total C(28,4) - C(16,4)...does this sound correct? Which then I came up with the answer of 18655. Anyone?

Answer 1

how do u take 28 here

Answer 2

i think its C(28,4)-C(12,4)

Answer 3

not sure though

Answer 4

Well I get the 28 because its' the total amount of cookies, then I subtract the oatmeal cookies out correct?

Answer 5

There are C(16, 4) ways of selecting 4 cookies without a chocolate cookie.
There are C(28, 4) ways of selecting 4 cookies, regardless of the number of chocolate cookies in the selection.
Therefore the number of ways of selecting 4 cookies that include at least 1 chocolate chip cookie is given by C(28, 4) - C(16, 4) = 18655.
So @littlenewme is correct.