i got some riddles...

these came from a book that i've been reading. if you've already heard these and know the answers, then..good for you. ok here we go.

riddle # 1: the light bulb problem.

imagine you are outside a closed room with no windows and one door. you cannot see inside the room until you open the door.

there are 3 light switches in front of you. each switch is connected to a different one of 3 light bulbs inside the closed room. all the light bulbs are currently off and thus all 3 switches are currently in the off position. you may flick on and off any of these switches as much as you like UNTIL you open the door and go inside the room to witness the state of the light bulbs. at that point you may no longer change the switches.

you may only open the door ONCE. THEN you must be able to tell which switch is connected to the light bulb.

in this scenario, how can you, with 100% certainty, tell which switch goes to which light bulb?

riddle # 2: the burning string problem

you have 2 lengths of string, which although they are not the same length, will each take exactly 30 mins for a flame to burn from one end of the string to the other. the strings do not burn evenly, so the position of a flame, as it burns through a string, will not afford you any specific knowledge of how much time the string has been burning for. all you know is that it takes exactly 30 mins for a flame to burn from one end of each string to the other end.

without using a timepiece, how can you use these 2 strings and matches to measure out exactly 45 mins with almost perfect accuracy?

bump

we got alotta smart ppl on here..i know one of you can solve these.

reply to post by LordInfamous


I know one thing...when I try to change the bulb on a lamp without turning it off, I sometimes burn my fingers.

I also know that burning the candle at both ends makes Jack a dull and sleepy boy.

Here's one. You're trying to drown an ant, but it's so small, it floats. How do you drown the ant without touching it?




[edit on 24-9-2007 by Badge01]

So what are the answers to the riddles?

I can't figure either of them out without more clues.

The first riddle: you leave one of the switches on for a couple of minutes and then you turn it off. Then you turn another one on and you enter the room. You'll have the lighted bulb, another one that's turned off, and the last that will be turned off but it will be hot to tuch.

The second one: you light one of the strings and at the moment it goes out you light the other one by both of its ends. It will burn in 15 minutes, meaning 45 counting the other one .

Wow! You did it.

I didn't put alot of thought into the one about the light bulbs, but I really racked my brain to try to figure out the one about the strings.

One thing about mind puzzles is that when you find the answer you feel like you should have known!!!

Good job.............