In the RC circuit below the switch is connected to A, at time $t = 0$, after being connected to B for a long time. The capacitor charges for $45 \:\text s$, then the switch is moved quickly to B ($t’ = 0$) and the capacitor begins to discharge.

The circuit parameters are: $\Delta V = 9 \:\text V$, $R_1 = 100 \:\text k \Omega$, $R_2 = 60 \:\text k \Omega$, and $C= 880 \: \mu \text F$.

What is the charge on the capacitor after $60 \:\text s$ of discharging ($t’ = 60\:\text s$)?