A school is offering 3 language classes: Spanish, French, and German. There are 100 students. There are 28 in Spanish, 26 in French, 16 in German, 12 in both Spanish and French, 4 in both Spanish and German, 6 in both French and German, and 2 in all three classes.
If 2 students are chosen randomly, what is the probability that at least 1 is taking a language class?
The answer is 149/189. I have no idea how to go about getting the answer.