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

[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.