Question

The sum of the first 8 terms of a
geometric progression is 6560 and the
common ratio is 3. The first term is-​

Answer 1

Step-by-step explanation:

As we know that ,

Sum of x terms of a GP =

a(rn - 1)

(when r > 1)

r - 1

Here , Sum = 6560 , n = 8 , r = 3

∴ 6560 =

a(38 - 1)

3 - 1

⇒ a =

6560 × 2

⇒ a = 2

6560

Answer 2

Sum of x terms of a GP =

a(rn - 1)

(when r > 1)

r - 1

Here , Sum = 6560 , n = 8 , r = 3

∴ 6560 =

a(38 - 1)

3 - 1

⇒ a =

6560 × 2

⇒ a = 2

6560