-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

x + 9, 10 and 4 are in G.P. The value of x is :

1. 16

2. 8

3. -16

4. 0