My eight favorite riddles (v. difficult) - Page 2
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StylishVODs
Sweden5331 Posts
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sdpgposd
United Kingdom1464 Posts
+ Show Spoiler + pm if i am right plz.. just take two pills if you die, you obv took the wrong two if u live u took the right two either way, you will never waste money because 1. you will have died and money will mean nothing or 2. you will live and know the other pill is a b | ||
diverse
Australia72 Posts
On September 19 2006 08:05 GrandInquisitor wrote: 7. There are 100 light bulbs lined up in a row in a long room. Each bulb has its own switch and is currently switched off. The room has an entry door and an exit door. There are 100 people lined up outside the entry door. Each bulb is numbered consecutively from 1 to 100. So is each person. Person No. 1 enters the room, switches on every bulb, and exits. Person No. 2 enters and flips the switch on every second bulb (turning off bulbs 2, 4, 6, ...). Person No. 3 enters and flips the switch on every third bulb (changing the state on bulbs 3, 6, 9, ...). This continues until all 100 people have passed through the room. How many of the light bulbs are illuminated after the 100th person has passed through the room? More specifically, which light bulbs are still illuminated, and why? Number Seven: + Show Spoiler + The number lightbulbs which are left illuminated will all have an odd number of divisors, because the number of divisors relates to the number of times the switch is moved on each lightbulb. These numbers are perfect squares, i.e. 1 4 9 16 25 36 49 64 81 100. | ||
VdP]DreaM
720 Posts
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Olmer
Poland320 Posts
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VdP]DreaM
720 Posts
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sdpgposd
United Kingdom1464 Posts
+ Show Spoiler + plz pm if i am right (this one is prrrrrrrrrobably wrong) ask the watch to show you blue if number 2 is correct or yellow if number 3 is correct. if it does nothing you know its number1, if it does show a colour you know its that particular box | ||
StylishVODs
Sweden5331 Posts
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diverse
Australia72 Posts
On September 19 2006 09:11 sdpgposd wrote: regarding number 2 + Show Spoiler + plz pm if i am right (this one is prrrrrrrrrobably wrong) ask the watch to show you blue if number 2 is correct or yellow if number 3 is correct. if it does nothing you know its number1, if it does show a colour you know its that particular box That's not within the capabilities of the watch, because it only answers yes/no. Regarding #8: You could continue eating the pills until there are 6 left in total, then mix them in water, divide into thirds and drink the solution >_> | ||
Olmer
Poland320 Posts
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sdpgposd
United Kingdom1464 Posts
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123bangbang
United Kingdom83 Posts
Erm...hmm someone tell me how to use a spoiler tag dammit! | ||
Resonate
United Kingdom8402 Posts
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Tsagacity
United States2124 Posts
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StylishVODs
Sweden5331 Posts
And even if it did work and you could find out if blue was yes/no you couldnt make a second question decide wich door held the car.. | ||
Ethenielle
Norway1006 Posts
![]() you pick two doors and ask if there are goats behind them, you get either blue or yellow. let's say you pick the two outermost doors. next up you pick either of those doors and the middle one, and ask if there are goats behind them. you can't get yes and yes, because then there would be three goats. you can get yes and no, then the car will be in the middle door. you can also get no and yes, and you can also get no and no, in which case the car must be in the door you didn't pick the second time around. thus: if you get blue/blue it can't be yes/yes, it must be no/no. same goes for yellow, of course. if you get a no/no, problem is pretty much solved. the car must be in the door you picked, because there will be a goat in the middle door. and a "no" gives us that there is a goat and a car behind the doors - car is in the door you picked, goat in the middle and goat in the one you didn't pick. now if you get a blue/yellow or yellow/blue, it's either a yes/no or a no/yes in both cases. in case blue/yellow is a yes/no, the car is in the middle door. in case it's a no/yes, the car is in the door you didn't pick. but all this doesn't really help either way, because you still can't know if blue/yellow is yes/no or no/yes. | ||
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Chill
Calgary25980 Posts
brick pushing down on boat displaces more water volume than volume of brick; water level falls | ||
badteeth
Netherlands1416 Posts
+ Show Spoiler + Which colour will the light be after i ask this question? | ||
StylishVODs
Sweden5331 Posts
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GrandInquisitor
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New York City13113 Posts
Also, twsan's solution is correct. | ||
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