Question

The first term of a geometric sequence is 3 and the multiplier, or ratio, is 5. What is the sum of the first 4 terms of the sequence?
A. 468
B. 450
C. 375
D. 243

Answer 1

Hey ,

a=3,r=5,n=4

Sn=a(r^n-1)/(r-1)
=3×(5^4-1)/(5-1)=3×624/4=3×156=468

Hence,a.)468 is right answer.

Hope it helps