a bag containing 3 red marbles, 2 green ones, 8 white ones, and 1 purple one. She grabs 3 of them. Find the probability that she has at least 1 green one.

Two out of 14 are green. That is 1/7 probability, on the first draw.

The probabilty of NOT getting green three times in a row, without replacement, is (6/7)(11/13)(10/12) = 0.6043660
The probability of getting one or more green is 1 minus that number = 0.3956