Hint to Puzzle #6: Switching 100 Light Bulbs
This hint is taken from the workings in the question, it seems second time around i can't come up with anything better:
First think who will operate each bulb, obviously person #2 will do all the even numbers, and say person #10 will operate all the bulbs that end in a zero. So who would operate for example bulb 48:
Persons numbered: 1 & 48, 2 & 24, 3 & 16, 4 & 12, 6 & 8 ........
That is all the factors (numbers by which 48 is divisible) will be in pairs. This means that for every person who switches a bulb on there will be someone to switch it off. This willl result in the bulb being back at it's original state.
So why aren't all the bulbs off?
There is an additional clue in that we are asked to consider bulb number 64....
© Nigel Coldwell 2004 - – The questions on this site may be reproduced without further permission, I do not claim copyright over them. The answers are mine and may not be reproduced without my expressed prior consent. Please inquire using the link at the top of the page. Secure version of this page.