Suppose there is a series of 100 light bulbs labeled 1 through 100 that all start in the off position. Person 1 walks in the room and turns on every light bulb. Person 2 walks in the room and flips the switch on every 2nd light bulb (i.e. he turns off all even numbered light bulbs). Person 3 walks in the room and flips the switch on every 3rd light bulb (turning some on and some off). This process continues until person 100 goes through and flips the switch on the 100th light bulb. Which light bulbs will be lit up at the end?
