The first term in a geometric sequence is 64, and the common ratio is 1/4. For what value of n is

\[t_n = \frac{1}{4}\]

**Answer:**A geometric series is represented as

\[t_1, t_1r, t_1r^2, t_1r^3, ......, t_1r^{n-1} = t_n\]

\[\frac{1}{4} = 64(\frac{1}{4})^{n-1}\]

\[4^{n-2} = 4^3\]

n = 5

**Final Answer: n = 5**