If 5th, 8th and 11th terms of a G.P. are x, y and z respectively, then which one of the following is correct?

1. y² = x²z²

2. y² = x² + z²

3. y² = xz

4. xyz = 1

Consider the G.P. a, ar, ar², …….., l. The kth term from the end is :

1. $\dfrac{l}{r^{k-1}}$

2. $\dfrac{l}{k}$

3. $\dfrac{al}{r^k}$

4. $\dfrac{l}{ar^{k-1}}$

Assertion (A): The 50th term from the end of the G.P. 4, 6, 9, $\dfrac{27}{2}, ……\dfrac{6561}{64}$ is $\dfrac{27}{2}$.

Reason (R): nth term from the end of a G.P. is given by $\dfrac{l}{r^{n-1}}$.

1. Both A and R are true, and R is the correct explanation of A.

2. Both A and R are true, but R is not the correct explanation of A.

3. A is true, but R is false.

4. A is false, but R is true.

Assertion (A): The sum of first 10 terms of the G.P. 3, 6, 9, 12, …… is 3096.

Reason (R): The sum of first n-terms of a G.P. is given by $S_n = \dfrac{a(r^n - 1)}{r - 1}$.

1. Both A and R are true, and R is the correct explanation of A.

2. Both A and R are true, but R is not the correct explanation of A.

3. A is true, but R is false.

4. A is false, but R is true.