2、There are 12 points on a circle, only one of which is a red point, and the rest are black points. Choose any 3 points as vertices, the difference between triangles with a red point and triangles without a red point is


【Analysis】There are $C_{11}^{3}=165$ without red dots, and $C_{11}^{2}=55$ with red dots, differing by 110.