If P and Q are two different matrices of order 3 × n and n × p, then the order of the matrix PQ is:

1. 3 × p

2. p × 3

3. n × n

4. 3 × 3

If $\begin{bmatrix} 2 & 4 \ 3 & 2 \end{bmatrix} \times P = \begin{bmatrix} 6 \ 8 \end{bmatrix}$, then the order of matrix P is:

1. 2 × 2

2. 2 × 1

3. 1 × 2

4. cannot be determined

If $\begin{bmatrix} 2 & 0 \ 0 & 4 \end{bmatrix}\begin{bmatrix} x \ y \end{bmatrix}$ = $\begin{bmatrix} 2 \ -8 \end{bmatrix}$, the values of x and y respectively are:

1. 1, -2

2. -2, 1

3. 1, 2

4. -2, -1

If $\begin{bmatrix} x & 1 \end{bmatrix} \begin{bmatrix} 1 & 0 \ -2 & 0 \end{bmatrix} = 0$, then the value of x is :

1. 0

2. 1

3. 2

4. -2