Did they correct for income?
Kids and young folks are more motivated to get $5 since they have low resources. If you are retired, why not take the chance on $20 vs a sure $5 you don't need?
Yes. They would need to.
The idea is this:
Would you take $1 or a coin flip for $2?
Would you take $5 or a coin flip for $10?
Would you take $10 or a coin flip for $20?
An `irrational' person would answer (Yes, No, Yes), or (No, Yes, No). Someone that answered all Yes or all No would not be inconsistent, nor would someone who answered (Yes, Yes, No) or (No, No, Yes), those people would be labeled as risk averse then risk loving.
As someone who has to sit through a lot of talks about research like this, GrumpySteen got it right in saying:
After a few dozen questions like that, I'd be so bored that I'd start choosing randomly without thinking about it just to get it over with. There's no way in hell I would seriously think about each and every question out of a list of 320.
A great paper on the topic is the 2001 paper "GARP For Kids", which asks the same question about children, and does a good job arguing that inconsistencies decrease with age going from young to college.