The point (m, -4) lies on the line x + y = 4, then the value of m is :

1. -6

2. 6

3. -8

4. 8

The point of intersection of the lines x + y = 8 and x - y = 0 lies on the line mx - 2y = 0; the value of m is :

1. 3

2. 4

3. 2

4. -2

The line x + y = 4 bisects the line segment joining the points (0, k) and (4, 0), the value of k is :

1. 2

2. 4

3. -4

4. -2