Answer: the first term is 5
Step-by-step explanation:
In a geometric sequence, the consecutive terms differ by a common ratio. The formula for determining the sum of n terms, Sn of a geometric sequence is expressed as
Sn = (ar^n - 1)/(r - 1)
Where
n represents the number of term in the sequence.
a represents the first term in the sequence.
r represents the common ratio.
From the information given,
S12 = 20475
r = 2
n = 12
Therefore,
20475 = (a × 2^(12) - 1)/2 - 1
20475 = (a × 4095)
20475 = 4095a
a = 20475/4095
a = 5
