Which scenario will drain the battery in the circuit diagram fastest: three 20 W bulbs in positions one, two, and three or 80 W bulbs at positions 1 and 3 with a gap at position two? How do you know?

See the explanation below.

Explanation:

If you connect the three bulbs 20 W each will have a total power of 60W.

Now we need to understand to assign the meaning of the word gap, that is, if the circuit is open at that point or if there is no bulb connected at that point.

If the circuit is open at Point 2, there will be no current in the circuit, so the battery will drain faster with the three bulbs 20W.

In the second event, where gap means that there are no bulbs connected at that point, it means that you have two bulbs connected in series of 80W each.

In this case the bulbs will consume 160W thus drain the battery faster than the three 20W bulbs connected in series.