The product of first five terms of a G.P. with first term a and common ratio r > 1 is equal to :

1. $\dfrac{a(r^5 - 1)}{r - 1}$

2. ar⁴

3. a⁵r¹⁰

4. $\dfrac{a(r^5 - 1)}{r}$

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

If a and l are respectively the first and the last terms of a G.P. having common ratio r > 1, then the sum to n terms of the G.P. is given by :

1. lar^{n - 1}

2. ar^ln

3. $\dfrac{lr - a}{r - 1}$

4. $\dfrac{lr^n - a}{lr - 1}$

The product of n terms of a G.P. with first term a and common ratio r, r > 1 is :

1. $\dfrac{a^n(r^{n} - 1)}{r - 1}$

2. aⁿrⁿ

3. $a^{n} r^{\dfrac{n(n+1)}{2}}$

4. $a^{n} r^{\dfrac{n(n-1)}{2}}$