Question

An urn contains 10 red balls, 10 green balls, and 5 white balls. 5 balls are selected. In how many ways can 5 balls be drawn if at least 3 are green?

Answer 1

The answer is 16002 (Teacher's answer) but I do not know how to get that answer.

Answer 2

Let's see, 25, chosen 5 at a time gives 6375600.
6375600/16002 = 398.42519685-- That can't be right.

Answer 3

i make it 12600

that's \[ C_{3}^{10} \times C_{2}^{15}\]