If the sum of n terms of an arithmetic progression S_n = n² - n, then the third term of the series is :

1. 2

2. 4

3. 6

4. 9

In the adjoining diagram, G is the centroid of △ ABC. A(3, -3), B(2, -6), C(x, y) and G(5, -5). The coordinates of point D are :

1. (2, -6)

2. (3, -6)

3. (6, -6)

4. (10, -6)

In the given diagram, O is the origin and P is the mid-point of AB. The equation of OP is :

1. y = x

2. 2y = x

3. y = 2x

4. y = -x