Answer: sum of the first 12 terms is
158944
Step-by-step explanation:
In a geometric series, successive terms differ by a common ratio. The formula for the sum of n terms, Sn in a geometric sequence is expressed as
Sn = a(r^n - 1)/(r - 1)
Where
a represents the first term of the sequence.
r represents the common ratio.
n represents the number of the terms in the sequence.
From the information given, we want to determine S12, so
n = 12
a = 4
r = 10/4 = 25/10 = 2.5
S12 = 4(2.5^12 - 1)/(2.5 - 1)
S12 = 4(59605 - 1)/1.5
S12 = (4×59604)/1.5
S12 =238416/1.5 = 158944
