Step-by-step explanation:
first rule of parallel circuits : the voltage is the same in the whole circuit, no matter where we measure.
so, we have 1.5V at every bulb.
second rule of parallel circuits : the total current is the sum of the individual branch currents.
so, if the battery really allows it, then we have 3 times 0.4 A = 3×0.4 = 1.2 A as current in the circuit.