Out of 15 students in a class, 10 are wearing blue shirts, 2 are wearing green shirts, and 3 are wearing red shirts. Four students are to be selected at random. What is the probability that at least one is wearing a green shirt?  Choose the most appropriate option:
A) 10/21
B) 20/31
C) 30/41
D) 40/51
E) 50/61
Total possible ways to choose 4 students out of 15 = 15C4 = 1365   The number of ways to choose 4 students with no green shirts = 13C4 = 715   P(no green shirts) = 715/1365 = 11/21   P(at least 1 green shirt) = 1 - 11/21 = 10/21   The answer is 10/21.
<result>A</result>
Out of 15 students in a class, 10 are wearing blue shirts, 2 are wearing green shirts, and 3 are wearing red shirts. Four students are to be selected at random. What is the probability that at least one is wearing a green shirt?