Given:
The explicit formula for a geometrc sequence is given:
[tex]a_n=500\times(0.5)^{n-1}[/tex]
To find the 6th term put n=6 here,
[tex]\begin{gathered} a_6=500\times(0.5)^{6-1} \\ =500\times(0.5)^5 \\ =500\times0.03125 \\ =15.625 \end{gathered}[/tex]
Hence, option B is correct.
