-1, k and -1 are three consecutive terms of a G.P., then

(i) k = 1

(ii) k = -1

Which of the following is valid ?

1. only 1

2. only 2

3. both 1 and 2

4. either 1 or -1

Three terms are in G.P., whose product is 27. The middle term is :

1. -3

2. 3

3. -3 and 3

4. -3 or 3

The common ratio of a G.P. is 2 and its 6^th term is 48. The first term is :

1. $\dfrac{3}{2}$

2. $\dfrac{2}{3}$

3. 1

4. 2

The common ratio of a G.P., whose 4^th term is 27 and 6^th term is 243; is :

1. 9

2. 3

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

4. $\dfrac{1}{9}$