Question

Please help! If r = 3 and the sum of the 6 terms of the geometric series is 3,640, what is the first term?

Answer 1

25

Answer 2

2.5? Or 25?

Answer 3

25

Answer 4

Formula for Geometric sum
Sn = a( r^(n) -1)/(r-1)
Sn = 3640
r=3
n=6
Hence 3640 = a(3^6 -1)/(3-1)
3640 = a( 729-1)/2
3640=a(728/2)
3640=a(364)
a= 10
a= 3640/1093