intro to geometric sequences (help pls)

Answer:
Option B
Step-by-step explanation:
The formula for geometric sequence is given by:
[tex]a_{n} = a_{1}r^{n-1}[/tex]
Where,
[tex]a_{n}[/tex] = nth term of sequence
[tex]a_{1}[/tex] = 1st term of the sequence
[tex]r[/tex] = common ratio (ration of the second term to the first term)
So,
Here:
[tex]a_{1}[/tex] = 12
[tex]r[/tex] = 6/12 = 1/2
Plugging in the values of [tex]a_{1}[/tex] and r in the above formula:
=> [tex]a_{n} = 12 * (\frac{1}{2}) ^ {n-1}[/tex]