There are 100 people in a theater. If 19 of these people have blue eyes, half of them have brown eyes, a quarter have black eyes, and the rest have green eyes, how many of them have green eyes? Think carefully first, then make a decision:
100 / 2 = 50 people in the theater have brown eyes. 100 / 4 = 25 people in the theater have black eyes. There are 50 + 25 + 19 = 94 people in the theater with either brown, black, or blue eyes. There are 100 - 94 = 6 people in the theater with green eyes. So, the answer is 6.