If the roots of the quadratic equation 2x² + 8x + k = 0 are equal, then the value of k is:

1. 2

2. 8

3. 4

4. none of these

The solution set for the quadratic equation 3x² - 18x = 0 is:

1. {6, 6}

2. {0, -6}

3. {0, 6}

4. none of these

The values of k for which the quadratic equation 9x² - 3kx + k = 0, has equal roots, are:

1. 0, 1

2. 0, 2

3. 2, 4

4. 0, 4