It’s the Friday Puzzle!

74

I have just placed some money into one of three boxes: a gold box, a silver box and a lead box.  Each box has an inscription.  At least one of the inscriptions is true and at least one of them is false.  The inscriptions are:

Gold box: The money is not in the silver box.

Silver box: The money is not in this box.

Lead box: The money is in this box.

You can only open one box, and if you open the box containing the money you get to keep the cash.  Which box should you open?

As ever, please do NOT post your answers, but do say if you think you have solved the puzzle and how long it took. Solution on Monday.

I have produced an ebook containing 101 of the previous Friday Puzzles! It is called PUZZLED and is available for the Kindle (UK here and USA here) and on the iBookstore (UK here in the USA here). You can try 101 of the puzzles for free here.

74 comments on “It’s the Friday Puzzle!

  1. JohnLoony says:

    About 30 seconds. Just went through all the possible combinations, and only one works.

    • Roland says:

      Yup, unless Richard made a mistake with his inscriptions, or made an untrue statement and put the money in his own wallet, or similar things you can expect from a magician and Richard ;-)

    • Moses says:

      True,True, False which gives you Gold. Obvious given today’s big event.

    • Moses, “please do NOT post your answers, but do say if you think you have solved the puzzle and how long it took.”

    • mikekoz68 says:

      At least this one is an easy one as you just have to go thru the combinations, but it sux having people like Moses post the answer after two comments- spoiling it for someone looking for clues. Does Richard ban or at least give a warning to guys like that?

  2. Chris says:

    Ok got it – I think. I went through each box and worked out whether the statements would be true or false if the money was inside; only one fulfils the rules.

    • One Eyed Jack says:

      Isn’t it amazing that there is always some moron that posts their answer within the first 10 posts? You are awesome, Moses! /sarcasm

      Now go find some children and tell them there’s no Santa Claus.

    • One Eyed Jack says:

      Errp! Replied to the wrong post. Now I’m the moron.

      Oh, Irony, you are an evil mistress.

  3. Anataboga says:

    20 seconds (though after last week I await the “solution” with trepidation)

  4. Hugh. Janus says:

    Got it. Easy one this week

  5. Niva says:

    Yes, pretty easy by elimination, 30 secs.

  6. Dave says:

    Took me less than a minute – its in the silver box

    • Paul Durrant says:

      It’s a shame you didn’t take a few more seconds before posting to read the full instructions, including “As ever, please do NOT post your answers”

    • As Paul points out, Richard has asked his readers not to share their answers before he reveals the solution on Monday. Additionally, your answer is incorrect, as if the money were in the silver box, all three inscriptions would be false.

  7. Mr. Smug says:

    A minute.
    I have two possible answers.

  8. JohnDavid says:

    If it is as easy as the 3 x 3 matrix then, yep about 20 seconds… but I never know if I’ve missed something!

  9. Paul Durrant says:

    Just a few seconds. Once the question has been read and the inscriptions have been read, the answer is obvious.

  10. rmb says:

    Just one minute. There are only three possibilities. Checking them one by one takes no time.

  11. Michael Sternberg says:

    This is the box of a plumber!” Oh wait …

    About a couple of minutes to be sure.

  12. Anonymous says:

    Think I’ve got it – used a logical process of elimination – now all I need to know is if I am right or just pleased with a wrong answer!

  13. JK Grence says:

    Brute force was a little too quick on this one.

  14. Anders says:

    My favourite book “What is the name of this book?” by Raymond Smullyan is full of puzzles like this, including exactly this one (the only difference is it wasn’t money in the box that the inscriptions were clues for) – it’s a great book, I highly recommend it

  15. walkymatt says:

    After we choose, will you show one of the others to be empty and give us a chance to swap?

  16. Klaas De Smedt says:

    1 minute (worked on the wrong clue the first 30 sec)

  17. Martha says:

    I got it in less than a minute, cos I read the comments

  18. Phil H says:

    Surely with the Olympics starting today the boxes should be Gold, Silver and Bronze. I think the money is, therefore, in a concealed bronze box.

  19. Peter Murphy says:

    Forget the money take the gold box

  20. Eddie says:

    Bring on the Olympics!

  21. Duncan says:

    A bit easy this one, there aren’t many possibilities.
    Any ideas on how we can stop people posting answers?

    • Martyn says:

      Have a ‘complain about this comment’ button to send it to moderation? My answer was 17.5.

  22. Lazy T says:

    Wot? no Merchant of Venice references?

  23. Anonymous says:

    I’ve noticed that people have been posting the answer more and more lately. Please could you not do this as it spoils the fun for everybody else. (And if you’re wrong you just look like an idiot.)

  24. mittfh says:

    That wasn’t too difficult to do – draw up a 3×3 truth table: one answer renders all three clues true, one renders all three clues false, while one renders two clues true and one false.

    However, it would be nice to have the ability to flag / report comments, so we can have an effecitve tool to use against those that don’t read the sentence that immediately follows *every* Friday Puzzle…

  25. Philipp says:

    Tool me 30 Seconds. Nice one, using the tertium non datur rule of reasoning.

  26. Bernard says:

    took me about 10 minutes! first time I’ve tried a ‘Friday puzzle’ so my brain isn’t quite prepared to do these things and struggled…

  27. Julia says:

    the real question is whether it’s just one person who keeps posting the answer using different names or if there’s a whole bunch of idiots around these days.

  28. elsiem says:

    About thirty seconds, to get an answer which contradicted my instinctive one, but which having READ THE ANSWERS EVERYONE HAS ALREADY POSTED I now know to be right. Agree with those requesting a “flag” button, although I don’t suppose Richard has time to spend weeding out the postings of people who can’t be bothered to read the instructions. Perhaps we just have to stop reading the comments until we are each happy with our own answers…

  29. Jenifer says:

    Got it. About twenty seconds.

  30. SimonP says:

    Of course the boxe might nested, which means the money could be in 1, 2 or all 3 of the boxes, re-jigging the order of the nesting might let the 3 conditions remain true for all of these variations. Anyone care to work this out?

  31. Bruce says:

    Brute Force with only 3 options possible 1min. Disappointed to see the answers posted.

  32. I see that I’m not the first to complain about this, but does anyone know why there suddenly seem to be a lot more people posting their answers in spite of Richard’s request not to? I don’t recall it having been a problem before, but I believe it’s happened several weeks in a row. Did Dr. Wiseman’s blog just suddenly shoot up in popularity or something?

  33. CFK says:

    @SimonP if the boxes were nested you had no choice but to open the one that contains the others.
    Anyway the best solution is not to open any box, grab the gold one, run away with it, sell its gold and profit from that.

    • Anders says:

      There’s not enough information to evaluate that. How much cash are we talking about? What is the gold content of the gold box? What is the current price of gold on the black market (stolen goods) – is it really more lucrative? Impossible to say. It saves a few seconds’ thinking, which most criminals have problems with anyway, so from that perspective perhaps…

  34. D says:

    Easy. :) Got it immediately.

  35. SilverMarc says:

    30 seconds, went the logic route. Somebody needs to smugly post that it’s the remaining box and negate the other two posted answers, at least one of which is ALREADY incorrect! :-)

    • Anders says:

      The money was always in the pink box, everyone knows that since the dawn of time

      Oh, you said smugly, not smuttily

  36. The Masked Twit says:

    If you allow one box to be inside another you can get a different answer from what I believe will be the official one.

  37. Got it right away just reading through the puzzle. This is a familiar format .I love tHis kind of puzzle because I CAN SOLVE IT!

  38. jerry says:

    Between 5 and 10 minutes. Once you see the key statement, it’s fairly easy, but I was slow in finding the key statement!

  39. Sari1967 says:

    I know which box I will open

  40. Anonymous says:

    Took me a minute of very tough headscratching.

  41. About 30 secs once I found a pen. Although I got it quickly enough I’m wondering if I missed something.

  42. Ken Haley says:

    Thought I’d heard this one before on CarTalk.com puzzlers. But this one is slightly different. Got it in about a minute.

  43. Toddy says:

    I solved it in about 2 minutes. My 10 yr old daughter enjoyed it, it took her about 5 mins.

  44. Merari says:

    two minutes

  45. RobbieMayhem says:

    Took me a couple of minutes, drew a rough truth table and looked at the possible answers that didn’t produce a conflict. I knew maths would come in handy one day :)

  46. Laith says:

    I’m in the ~30 seconds camp this time, and that includes thinking it through a second time to be sure I’m right.

    so I’m probably wrong :)

  47. Ian says:

    Oh, I like that one, thanks: rather clever :) Took me about a minute to get it, double-checking just to be sure :)

  48. Zach says:

    30 seconds. Hilarious.

  49. charm says:

    10 secs :D
    i m a champ!!!!!!!!!!!!!

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