Find the sum of the following geometric progressions :
1, 3, 9, 27, … to 8 terms
Common Ratio = r =
∴ Sum of GP for n terms = …(1)
⇒ a = 1, r = 3, n = 8
∴ Substituting the above values in (1) we get
⇒
⇒ (38 – 1)/2
⇒ 3280