Here are some assumptions you can safely make:
When a light switch is flipped up, the light is on and when the switch is flipped down, the light is off.
There are no dimmers on the light switches.
You can’t see whether or not the lights are on from any- where downstairs.
You must go upstairs to determine if a light is on.
It’s daytime, so even if you went outside you still wouldn’t be able to tell if a light is on or not.
You are alone. (Poor you.)
If there were just two light switches and two lights, this would be easy. But with three light switches and three lights, it’s more difficult.
Once again, if you get stuck, try applying the thinking tech- niques that appear later in the book. The more you practice the techniques, the more they will become second nature.
Head to www.kevincarroll.com for the answer.