# It’s the Friday Puzzle!

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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 on “It’s the Friday Puzzle!”

1. Mervulon says:

Solved immediately.

• Navneeth says:

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.

• Turd says:

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

2. Eddie says:

4 seconds

3. Rob J says:

Got it almost immediately!

4. Alex says:

Done! Looks like there’s a few arrangements for this.

5. Alex says:

“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.

6. Roland says:

Seems again a definition puzzle. Probably on Monday there will be another discussion about this puzzle 😉

7. Nanda Gunawardhana says:

10 seconds….

8. KMR says:

I certainly can… With ease! Good puzzle.

9. kroketje says:

immediately, an easy one 🙂

10. Dave says:

• Simon Taylor says:

Yes. Do we need a vote?

• Phil McCavity says:

Yes

• Jerry says:

What comment?

11. Hugh Jarse says:

I agree, Dave did not reveal the answer. I wish the pedants would STFU

12. Stephen says:

I’ve Got three different answers within a minute, depending on how I read the question!

13. Niva says:

Can I do it? Yes I got the answer immediately.

14. Rob says:

Instantly

15. Paul Durrant says:

And yes, Dave, you did give the answer.

16. Dr. K says:

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.

• Hugh Janus says:

Tedious

17. Simon Taylor says:

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.

18. Stupid Illliterite Sociopath says:

Dr K,
The copyright notices and publisher information are the best bit of the book.
Enjoy!!

19. Michael Michael says:

Done. Several solutions on the same principle.

20. timdowd says:

10 seconds… After I got the bags and balls from the shed…

21. Simon Taylor says:

Thankfully, Dave and the other revealer have been deleted.

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

• Stevie says:

That’s why I didn’t see their answers.
Got it quickly too…… If I’m right, that is.

• Jarvis Cocker says:

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

• Nanny Mouse says:

Jarvis/Dave

• Liverpool Div says:

Hilarious Jarvis.

(We are laughing at you, not with you)

• Anonymous says:

OK Nanny Mouse:-

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

• Simon Taylor says:

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.

22. little chap says:

I think I am wandering from simple ways to solve the wiseman’s problems!

solved though.

23. Sam says:

I’ve got a way but it sounds a bit like cheating…

24. Berhard says:

there is more than one solution, and got the first one immediately…

25. Phil H says:

1 second and slightly longer to check I hadnt missed something

26. Anonymous says:

I thought I must be doing it wrong somehow because I got it so quickly, but it seems I’m not the only one who saw it right off the bat.

As a subsidiary question – how many possible answers are there to RW’s question?

• Ben Saunders says:

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.

• SimonP says:

It feels like there must be a large number of solutions.

• Photon Boy says:

4

• simontaylor says:

• Emlyn says:

I found 68 answers, might have missed a few more…

• Anon says:

Simon, Photon Boy,
You are underestimating.
You need to think outside the envelope.

• Emlyn says:

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“.

28. Ophelia Balls says:

I think the answer is dependent on whether or not one or more of the bags are biodegradable

29. Yat says:

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.

• Wigan FC says:

What part of the question is very poorly worded Yat?

30. Chris says:

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!

31. |After a min. I got AN answer-I’m not sure if it’s THE answer-we’ll see on Monday…

32. Christian says:

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.

• simontaylor says:

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

• JohnLoony says:

• mikekoz68 says:

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.

• Christian says:

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.

33. Neil says:

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.

34. Tibi says:

There’s no solution unless you consider the containment relation to be transitive.

35. Ian says:

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

36. Ken Haley says:

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. 🙂 ).

37. Stan says:

Got it in about 15 seconds. Nice to have an easy one.

38. dlesage says:

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!

• Niva says:

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

39. Bruce says:

40. physicalist says:

Got the answer(s) in seconds. Felt pretty proud — until I saw that everyone else got it straight away too.

41. JohnLoony says:

Ultra-easy; immediately obvious. About half a second to get the most obvious solution. I presume there are lots of solutions.

42. Anonymous says:

got it less than 30 seconds…

43. Hamilcar Barca says:

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.

• Hamilcar Barca says:

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…

44. jeffjo says:

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.

45. Zach says:

Got it in about two minutes. Yes you can. Good stuff.

46. Gee, Chris, you bat your brains out just like I do and to no avail. Don’t you hate it when the answer is simpler that you imagined?

47. Mike Rablins says:

One minute. Once you open your mind these become easy.

48. Phil Pearce says:

I THINK I have it, but my solution might be considered to be cheating… Time will tell!

49. Jerry says:

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!

50. therublezoo says:

This is a puzzle that can totally be OVER THOUGHT but if you just read it and follow it, it is EASY!

51. beaky says:

Took 10 seconds. There are at least two answers.

52. dharmaruci says:

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).

53. Paul Murray says:

10 seconds – “it’s impossible”
12 seconds – “Oh. Right. Ok.”

54. Very good blog post. I absolutely love this site. Continue the good work!

55. Peter says:

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.

56. This really is exactly what I had been searching for, many thanks