Recall from Example 1 that whenever Suzan sees a bag of marbles, she grabs a handful at random. She has seen a bag containing three red marbles, five green ones, four white ones, and three purple ones. She grabs eight of them. Find the probability of the following event, expressing it as a fraction in lowest terms. HINT [See Example 1.]

Question

Recall from Example 1 that whenever Suzan sees a bag of marbles, she grabs a handful at random. She has seen a bag containing three red marbles, five green ones, four white ones, and three purple ones. She grabs eight of them. Find the probability of the following event, expressing it as a fraction in lowest terms. HINT [See Example 1.]
She has at least one green one

Reiny · Accepted Answer

I don't know what example 1 is, thus I don't know how you are taught to do these.

Here is how I would do it
Number of ways to choose 8 from 15 = C(15,8) = 6435

at least one green ---> exclude the case of no green
number with no green = (10,8) = 45
so the number with at least one green = 6435-45 = 6390

prob(of at least one green) = 6390/6435 =142/143

or 1 - 45/6435 = 142/143