The sum of the first 8 terms of a geometric progression

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

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