First a quick bit of news – tomorrow I am interviewing comedian and actor Alan Davies as part of ‘BBC at the Edinburgh Festival’.  Tickets are available from 11am tomorrow at their venue.

Now, the puzzle.

You have nine tennis balls and four shopping bags.  Your challenge is to put the balls in the bags in such a way that there is an odd number of balls in each bag.  That is, each bag must contain 1, 3, 5, 7 or 9 balls.  Can you do it?

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.

83 comments

    1. Once you openly say what the solution is essentially, you’ve spoilt it for everyone else. I’m sure Jim from a door further away from yours is appreciative of your efforts.

    2. Maybe the instructions should change to “Do not read any comment till you wanna know the answer.”

  1. “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.”

    Not hard is it.

  2. I agree that, technically, you did not provide the answer. But then, that’s the same as saying that, technically, I haven’t finished reading Richard’s book because I still haven’t read the copyright notices and publisher information right after the title page. Your comment counts as an answer for anyone who is not a complete moron.

  3. Got it, then scrolled down and confirmed my answer by two people who did not read the question.

    Ruins it with the suspense of thinking about it over the weekend.

    Maybe Richard should put the “don’t post the answer” instruction first before the question, then people who demonstrate that they are not actually that clever might see it.

  4. Thankfully, Dave and the other revealer have been deleted.

    They’ve taken their balls and bags to play somewhere else!

    1. OK Nanny Mouse:-

      Dave is Pussy Riot to your Putin, Simon.
      Of perhaps you are just a “moralising slut”

    2. Jarvis – I don’t know if that’s a compliment or an insult. I have no idea what you are talking about! Very cryptic, I’m sure.

    1. It seems there are only two possible answers – yes and no – which are exclusive. So only one right answer, though there may be different ways of reaching it.

    2. And by that I mean 68 ways of arranging the balls in the bags assuming all of the balls have to be used (otherwise there would be even more ways), the only right answer to RW’s question is “yes“.

  5. Well, I guess some people here should read more carefully “each bag must contain 1, 3, 5, 7 or 9 balls”.
    So if a solution contains empty bags, it’s wrong.
    Except if the problem is very poorly worded, of course. In that case it is just plain obvious.

  6. Spend 20 minutes trying to work it out conventionally then gave up. Went back to have another look an hour later and got it immediately. Very clever!

  7. It can’t be done. There probably is some kind of “solution” but whatever the solution is, you can’t get 9 by adding 4 odd numbers. So, the solution will probably revolve around how to cheat the premise.

    1. Christian. Not at all. Read the puzzle again. It can be done without cheating. Or come back on Monday for the solution!

    2. I agree with Christian- (I agree with a Christian? lol never thought I’d say that!) the only way I can get a “solution” is to “cheat” a little which has to be the answer cuz you can’t get 9 by 4odd numbers. If this is the way they are getting it then there’s way more than one correct answer.

    3. My statement stands. I call “put a bag inside another” for changing the premise rather than solving the puzzle. I still claim it’s not solvable and that the solution is cheating.

  8. 10 seconds for first answer, then another minute thinking it through to get a second (hopefully correct) answer.

    Oh, and thanks to whoever is pruning the forum of spoiler posts.

  9. Hope the weekend goes well, Richard. Thanks for another delightful puzzle. Solved it immediately. Have an excellent weekend, with much inspiration and success 🙂

  10. Got the answer almost immediately, but I’ve heard something like it before. But there’s another less obvious answer that works because of the way the question’s worded. I’ll post Monday (if I remember. 🙂 ).

  11. Depends on your definition of “odd”. From my point of view, putting any number of tennis balls in shopping bags is pretty odd indeed, so it’s quite possible by distributing the balls any way you like!

    1. No, Richard clearly defined what “odd” meant. “Each bag must contain 1, 3, 5, 7 or 9 balls.”

  12. First the two children puzzle, now this. It must be the new fashion in puzzling: word the puzzle so vagely that there are multiple interpretations. Then the challenge becomes guessing which interpretation Richard has chosen.

    Did he intentionally leave out the word “all”? In that case we get the answer with four permutations. Or maybe “all” is implied, and we get the answer with one permutation.

    But I have to choose one, don’t I? Because that’s the challenge. The new fashion requires reading Richard’s mind. I’m going to guess that the omission was a linguistic oversight and he has chosen the interpretation with one permutation. He will, of course, provide a suitably complex algebraic proof on Monday.

    1. One of the wonderful things about “new fashion” puzzling is that you can give away your answer and nobody cares, as long as you don’t give away the/an answer to the original puzzle. You just have to refer to those answers indirectly. I so like the new fashion…

  13. Knew the answer (or at least, how to get it) before finishing reading the question. Once I saw the number of bags, it was all over.

  14. I read this puzzle late last night and after a few trial and error attempts, decided to go to bed and check it out in the morning. While brushing my teeth, I thought about: 1) how to represent odd numbers algebraically and 2) how to represent the sum of four odd numbers. By the time I had finished brushing, I had both the answer and its proof!

  15. surely the only ans is that i throw 5 balls away and put 1 in each bag. (it is now mon somwwhere in the world, so ans is allowed).

  16. My dream retirement locale is Portugal! I have study that it is THE place to retire in Europe due to a lower than average cost of living , a large coastline (so it’s easier to live close to the ocean), and much less citizenship/visa red tape.

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