And again

[chuckro]

This was inspired by Brian's comment on my last one. I'm just a puzzling machine. Please let me know, again, if you find more than one unique solution or a contradiction in my clues. Edit: Some minor corrections have been made based on comments.

This is the tale of six brothers: Arnold, Barry, Chester, David, Edward, and Frank. None of them are twins, and each of them has a whole-number age. What are the brothers' ages?

1. Frank is two years older than Barry.
2. Edward is half Chester's age.
3. David is two-thirds Arnold's age.
4. Half of the brothers can legally drink in the US.
5. None of the brothers has reached retirement age.
6. Two of the brothers' ages are prime numbers. Frank's age isn't one of them.
7. David was born between Edward and Barry.
8. Chester is the oldest, Arnold is second-oldest.
9. Barry is six years older than Edward.

Comments

[fairylane.livejournal.com]

I know this is a "bah" sort of comment, but you might want to clarify where they can legally drink, depending on where your audience is...

Yes...another Canadian heard from...

[tigermelp.livejournal.com]

Trickier.

Chester is 26
Arnold is 24
Frank is 21
Barry is 19
David is 16
Edward is 13

I will playtest for you anytime. :)

[tigermelp.livejournal.com]

Also, you should probably say something like, "what are the brothers' ages?"

And, if you want to get nit-picky (like, if you're publishing them somewhere), clue #3 should read, "David is two-thirds Arnold's age."

[feiran.livejournal.com]

Chester is 28
Arnold is 24
Frank is 21
Barry is 19
David is 16
Edward is 13

The only thing that I found unclear about this one is the matter of a "round number." At first I thought you meant even numbers, or multiples of 5 or 10 depending on how you'd round them. That couldn't be right if numbers were supposed to be prime, so I gathered that you meant whole numbers, but you might want to state that outright.

[feiran.livejournal.com]

Sorry, typo: Chester is 26.

[edgehopper.livejournal.com]

Definitely trickier--I agree with the other two answers up there, but haven't looked for alternatives (though I'm pretty sure I can prove there aren't any.)

Also, change 6 to "Three of the brothers' ages are prime", and we have the Canadian answer:

Arnold: 21
Barry: 17
Chester: 22
David: 14
Edward: 11
Frank: 19

Nice puzzle--no comments other than repeating what's up there--call them whole numbers instead of round numbers, and specify that it's an American drinking age.

[shnayder.livejournal.com]

Yup-a bit trickier. I like :)

[esprit-du-tigre.livejournal.com]

aaaaaand moving along to this one. (I did them both then commented =)

Yup, same answers as above. I don't like these "analog" puzzles as much as the "discrete" puzzles such as the class/level puzzle before, but that's just my personal preference. I hate numbers and basically math in general.

I wonder, though. Is there a way to solve this without resorting to guesswork and "plug-and-chugging" at some point? The way I solve these puzzles is I deduce as much as I can from the information provided, and if I'm unable to prove firmly one or more of the values, I start picking reasonable values for an important variable (in this case, Barry's age, since knowing that opened up a world of information) and seeing if they fall into place. Did anyone actually solve this without resorting to this method? And if so, please share the process.

[edgehopper.livejournal.com]

2 of the brothers' ages are prime. Those have to be Edward and Barry, as the others have to either be divisible by a whole number (A, C, D) or are Frank. So Edward and Barry have two prime ages with a difference of 6. They also have to be grouped around 21, so we only get the pairs

11-17
13-19
17-23

Test from there. But then note that 2 more than the higher number (Frank) has to be composite, so the only set that works is 13-19-21. Test and check that it works.

[chuckro.livejournal.com]

Amusingly enough, that's the train of thought I followed while setting the puzzle up.

[ivy03.livejournal.com]

That was - algebra. System of equations. Yay.

I got the same as answers as everyone else. Yay me.

OK, work.