If the mid-point of the line segment joining the points P(a, b - 2) and Q(-2, 4) is R(2, -3), then the values of a and b are

1. a = 4, b = -5

2. a = 6, b = 8

3. a = 6, b = -8

4. a = -6, b = 8

The coordinates of the point which is equidistant from the three vertices of △AOB (shown in the adjoining figure) are

1. (x, y)

2. (y, x)

3. $\Big(\dfrac{x}{2}, \dfrac{y}{2}\Big)$

4. $\Big(\dfrac{y}{2}, \dfrac{x}{2}\Big)$

If one end of a diameter of a circle is (2,3) and the centre is (-2, 5), then the other end is

1. (-6, 7)

2. (6, -7)

3. (0, 8)

4. (0, 4)

The fourth vertex D of a parallelogram ABCD whose vertices are A(-2, 3), B(6, 7) and C(8, 3) is

1. (0, 1)

2. (0, -1)

3. (-1, 0)

4. (1, 0)