1 Topic by jackneve (edited by jackneve 2022-09-23 08:25:12)

  • Registered: 2022-01-21
  • Posts: 382

Topic: Tangled logic

Would your answer to this question be "no"?

(I'm remembering the question which I found in a book last night. I think I've got it right.

Tip: try both answers "yes" and "no"

  • From: Essex England
  • Registered: 2022-01-30
  • Posts: 165

Re: Tangled logic

That question reminded me of this old chestnut - can you work it out?

You are stranded on a desert Island which was inhabited by just two tribes, one tribe always told the truth and the other tribe always lied.

You had had no idea what tribe the person you were talking to came from. How could you phrase a question to that person, which would elicit the truth every time, regardless of what tribe the person was a member off?

3 Reply by jackneve (edited by jackneve 2022-09-23 12:45:27)

  • Registered: 2022-01-21
  • Posts: 382

Re: Tangled logic

This is also well known  in this version:

You’re in a room with two doors. There’s a guard at each door. One door is the exit, but behind the other door is something that will kill you. You’re told that one guard always tells the truth and the other guard always lies. You don’t know which guard is which. You are allowed to ask one question to either of the guards to determine which door is the exit.

What question should you ask?

There are two solutions to this problem, and the second is so different and is not normally given that I will post it in a few days if no-one tells it first.

  • Alfred
  • Alfred
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  • Registered: 2022-01-21
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Re: Tangled logic

jackneve wrote:

There are two solutions to this problem, and the second is so different and is not normally given that I will post it in a few days if no-one tells it first.

I only know of the answer which is the same as the answer to the problem posed by Albert, so I’ll be interested to find out what the alternative answer is!

"Has it ever struck you that life is all memory, except for the one present moment that goes by you so quick you hardly catch it going?"
― Tennessee Williams
  • Registered: 2022-01-21
  • Posts: 382

Re: Tangled logic

I've forgotten it, so I shall have to look it up again.
Sorry.

I've had a lot of bother lately. First my desktop wouldn't turn on - due to blown electrolytics. Substituted older psu - nominally same spec, but terrible tendency to not come on or to cut out. Had to power hard drives from ancient straight transformer rectifier psu. Computer guru swapped old psu for modern more powerful version- done the trick. Also, my main data storage drive wasn't seen by the pc, and it turns out to have a blown chip. Thank goodness, the control card is joined to the HD body by a set of pressure contacts, and my computer guru says that I can put in a card from an identical HD, buying on line, no soldering required. That might do the trick. Otherwise, its off to a data retrieval firm. Cost!!!

Simultaneously, my household CH & HW system gave up, and that nice plumber had to come round for several days. He had to replace the pipe runall the way through the house from the cold water header tank in the loft to the downstairs HW cylinder, and later we had to change the motor head on the HW-boiler-to-cylinder cut off valve, and then we found the pump impeller had frozen. He couldn't get to old pump body out - threads really immoveable. But as it was the same make and model pump he was able to swap the motor impeller head. All lovely now.

  • Registered: 2022-01-21
  • Posts: 382

Re: Tangled logic

The alternative question is:

If you ask any guard, "is the truth telling guard standing in front of the door that leads to freedom?", if he says no you always go to the opposite door. If he says yes you simply go through that door.

BTW, about one of the problems assailing me mentioned in the last posts, swapping control cards between otherwise identical HDs doesn't work in my case. Sadly, looks like lotsa dosh needed to recover data!