How much current flows through a 12-ohm flashlight bulb operating at 3.0 volts?

From the ohms law, the current through a conductor is directly proportional to the potential difference. Thus we get the equation I = V/R
where I is the current in Ampheres, V is the voltage in volts and R is the resistance in Ohms.
Hence; I = 3/12
               = 0.25 Ampheres
Thus, the current through the flashlight is 0.25 Ampheres