A man has three sons. One day, the postman asks about their age. The man wants to be edgy and mysterious so he says :
"If you multiply the ages of my sons, you get 72.
- kk." the postman answers.

"If you add their ages together, you get the amount of letters you have left in your briefcase."
The postman looks in it, and says :
"I still can't find..."

Lastly the man tells him :
"My youngest son has blue eyes."
- Oooh, I know now!


They highfive and give each other "The Nod™". Then they go back to their miserable life. The postman died 14 years after this event, from knee cancer. The man moved to Spain with his sons and now works in a mussels farming industry.

How old are the man's sons?