The common difference of the A.P. $\dfrac{1}{k}, \dfrac{1 - k}{k}, \dfrac{1 - 2k}{k}$, …… is :

1. −k

2. k

3. 1

4. −1

If the nth term of an A.P. is given by (3n + 2), then the sum of its first three terms is :

1. 21

2. 24

3. 27

4. 32

The common difference of the A.P. : $\dfrac{1}{3}, \dfrac{(1 − 3p)}{3}, \dfrac{(1 − 6p)}{3}$, … is:

1. p

2. −p

3. $\dfrac{1}{3}$

4. $\dfrac{-1}{3}$

The next term of the A.P. $\sqrt{3}, \sqrt{12}, \sqrt{27}, \sqrt{48}$, … is:

1. $\sqrt{72}$

2. $\sqrt{68}$

3. $\sqrt{75}$

4. $\sqrt{56}$