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)

In the given diagram, △ ABC ~ △ PQR and $\dfrac{AD}{PS} = \dfrac{3}{8}$. The value of AB : PQ is :

1. 8 : 3

2. 3 : 5

3. 3 : 8

4. 5 : 8

A right angle triangle shaped piece of hard board is rotated completely about its hypotenuse, as shown in the diagram. The solid so formed is always :

(i) a single cone

(ii) a double cone

Which of the statement is valid ?

1. only (i)

2. only (ii)

3. both (i) and (ii)

4. neither (i) nor (ii)