A Hypothetical RC Circuit

$R(a) = \sum_{n=1}^{\infty} \frac{1}{a^n} = \frac{1}{a-1} \qquad \qquad C(a) = \sum_{n=0}^{\infty} \frac{1}{a^n} = \frac{a}{a-1}$

An RC ciruit consisting of a multitude of resistors ($R$) in series followed by a multitude of capacitors ($C$) in parallel is prepared such that the resistance and capacitance can be calculated with the series written above. At $a= 3$, calculate the voltage ($V$) of the capacitor when it has charged for $t = 2.5 \space \text{seconds}$, where the circuit's power supply voltage ($V_{\circ}$) is $14 \space \text{volts}$.

Round your answer to three significant figures.

Note: $V(t) = V_{\circ}(1-e^{N})$ where $N = \frac{\text{-t}}{\text{RC}}$.