How it works:
The electricity from the dry cell battery flows through the wires to all the three different bulbs through the 3 paths (3 different arrows - black red green)
When two of the bulbs are lit up, the brightness will be the same as it is a parallel circuit.
When three three bulbs light up all of the will be the same but will be dimmer than if it was only 2 bulbs or one bulb light up.
If it is in a series circuit one bulb is dependent on the other however in a parallel circuit it is no dependent which is more suitable for this activity.