$\begin{bmatrix$}[r] 7 & -4 \ 3 & 8 \end{bmatrix} = \begin{bmatrix}[r] p & q \ r & s \end{bmatrix}\begin{bmatrix}[r] 1 & 0 \ 0 & 1 \end{bmatrix}, the values of p, q, r and s are respectively :

1. p = 7, q = 3, r = -4 and s = 8

2. p = 7, q = -4, r = 3 and s = 8

3. p = -4, q = 7, r = 8 and s = 3

4. p = 3, q = 8, r = 7 and s = -4

If the sum of three numbers in A.P. is 48; then the middle term is :

1. 16

2. 18

3. 12

4. 6

In the given figure, ∠BCA = ∠CDA = 90°, then the value of $\dfrac{CD}{AD}$ is :

1. $\dfrac{BC}{CA}$

2. $\dfrac{BD}{AD}$

3. $\dfrac{BD}{CD}$

4. $\dfrac{CA}{BC}$

A cylindrical can with radius 10 cm and height 20 cm, is kept on a horizontal surface and then filled with water upto 10 cm. The total wetted surface of the can is. (Take π = 3.14)

1. 871 cm²

2. 624 cm²

3. 314 cm²

4. 942 cm².