If A = $\begin{bmatrix$}[r] -1 & 2 \end{bmatrix} \text{ and } B = \begin{bmatrix}[r] 1 & -2 \ 0 & 3 \end{bmatrix}. Which of the following operations is possible ?

1. A - B

2. A + B

3. AB

4. BA

If x² + kx + 6 = (x - 2)(x - 3) for all values of x, then the value of k is :

1. -5

2. -3

3. -2

4. 5

If the roots of equation x² - 6x + k = 0 are real and distinct, then value of k is :

1. > -9

2. > -6

3. < 6

4. < 9

Which of the following is/are an Arithmetic Progression (A.P.) ?

(i) 1, 4, 9, 16, ……..

(ii) $\sqrt{3}, 2\sqrt{3}, 3\sqrt{3}, 4\sqrt{3},$ …………

(iii) 8, 6, 4, 2, ………..

1. only (i)

2. only (ii)

3. only (ii) and (iii)

4. all (i), (ii) and (iii)