On an otherwise deserted and isolated island, 200 perfect logicians are stranded. The islanders are perfectly logical in every decision they make, and they will not do anything unless they are absolutely certain of the outcome. However, they cannot communicate with each other. They are forbidden from speaking with one another, or signing, or writing messages in the sand, else they be shot dead by the captain of a mysterious ship that visits the island each night.Of the 200 islanders, 100 have blue eyes, and 100 have brown eyes. However, no individual knows what color their own eyes are. There are no reflective surfaces on the island for the inhabitants to see a reflection of their own eyes. They can each see the 199 other islanders and their eye colors, but any given individual does not know if his or her own eyes are brown, blue, or perhaps another color entirely. And remember, they cannot communicate with each other in any way under penalty of death.Each night, when the captain of the ship comes, the islanders have a chance to leave the barren and desolate spit of land they have been marooned on. If an islander tells the captain the color of his or her own eyes, they may board the ship and leave. If they get it wrong, they will be shot dead.Now, there is one more person on the island: the guru, who the islanders know to always tell the truth. The guru has green eyes. One day, she stands up before all 200 islanders and says:I see a person with blue eyes.Who leaves the island? And when do they leave?
Name: JasonOccupation: DJBroadcast: FM/AM
Heres a fun one for people.......What is interesting about this Radio Presenters business card?Name: JasonOccupation: DJBroadcast: FM/AMNo posting spoilers Cheers!
How many letters are there in the answer to this question?(this is a separate puzzle btw, not a response to any of the others)
Hi All, I proper love logic puzzles (stereotype autistic :p )Does anyone know any good ones or links to good ones?
Quote from: Banana finger on August 06, 2021, 09:33:38 amHi All, I proper love logic puzzles (stereotype autistic :p )Does anyone know any good ones or links to good ones? Have you tried Olympic scoring?
Quote from: Banana finger on August 06, 2021, 09:33:38 amHeres a fun one for people.......What is interesting about this Radio Presenters business card?Name: JasonOccupation: DJBroadcast: FM/AMNo posting spoilers Cheers!Got it.
You have 12 balls of identical appearance and a set of scales (the sort where you put different things on either side and check which is heavier, not the sort that measures weight in kilos or whatever). 11 of the balls weigh exactly the same and one is heavier. What is the minimum number of weighings that you can do to work out which ball is heavier and how do you do it?How does the answer change if 11 balls weigh the same and 1 is heavier or lighter, but you don't know which?
Quote from: Stabbsy on August 06, 2021, 12:27:06 pmYou have 12 balls of identical appearance and a set of scales (the sort where you put different things on either side and check which is heavier, not the sort that measures weight in kilos or whatever). 11 of the balls weigh exactly the same and one is heavier. What is the minimum number of weighings that you can do to work out which ball is heavier and how do you do it?How does the answer change if 11 balls weigh the same and 1 is heavier or lighter, but you don't know which?1st weighting. Split into 6 each side. One side will be heavier.2nd weighting. Split heavier 6 into 3 each side. One side will be heavier.3rd weighting. Split heavier 3 into 1 against another 1 until find heaviest. Minimum weightings = 3, maximum weightings = 4 Answer doesn't change if one is lighter, except change 'split the heavier side' to 'split the lighter side'.?
Probably a common one. I like it as it doesn't rely on maths but lateral thinking. You are outside a room, there are 3 switches which correspond to 3 light-bulbs inside the room. you don’t know which switch corresponds to which bulb and you can't see inside the room. You can only enter the room with the bulbs and come back out once. You can not use any external test equipment. How do you find out which bulb corresponds to which switch?
I think you’d have to weigh both of the sets of 3, 2 of these would be the same and 2 uneven, then you proceed to the individual weighing as before, so one extra weigh?
It's trying to answer a different question - you're looking to discard as many of the same weight as quickly as possible. Not specifically look for the outlier. So is it something like:Start with any 50% (6 balls) and split them, 3/3. If they weigh equal then you can discard those 6, because you know the outlier must be among the remaining 6. If not equal then you can discard the unweighed 6, because you know they'll be equalSo that's 1 weigh.Then you're left with 6. Apply same theory - take 50% and split 3/3. If equal you can discard those 3 because the outlier must be in the remaining 3. If unequal you can discard the unweighed 3.2 weighs.That leaves you with 3.Take any 2 and split 1/1, weigh. If equal you know the outlier is the unweighed one. If unequal you've found the outlier by weighing.So 3 weighs. Same as previous.
There was a girl who worked in the coffee shop i always go to.I got chatting to her once. After that she was really nice to me monday to friday but always ignored me on the weekend.What was her deal?
Quote from: Banana finger on August 07, 2021, 08:08:03 amThere was a girl who worked in the coffee shop i always go to.I got chatting to her once. After that she was really nice to me monday to friday but always ignored me on the weekend.What was her deal?Identical twins? The chatty one worked weekdays and her sister worked the weekend?
