We can determine the charge of the system by doing some dimensional analysis of the values given above. We are given the voltage and the potential energy of the system. Voltage is the energy per charge so it will have units of J/C. So, we can determine the charge, with units C, by dividing the energy with the voltage.
Charge = Energy / volatage
Charge = 0.025 / 325 = 7.69x10^-5 C