Problem #PRU-5144

Problems Mathematical logic Invariants

Problem

There are 12 light bulbs placed on top of the numbers on a clock face. Initially, only the bulb at 12 is on. We can choose any 6 consecutive bulbs and change their state simultaneously, that is, if any were on, we turn them off, if any were off, we turn them on. Can we perform this operation multiple times so that in the end only the bulb at 11 is on?