So, this is my first attempt at a puzzle on here. I've no idea how easy/hard this will be.
Puzzle: Barry, Susan and Jonah are friends. One day the three walked into a candy shop. The three later walked out with fifteen pieces of candy to share between them, as friends typically do.
A little while later, Barry's younger sister, Alicia, walked into the same store. She left with six. Then Susan's younger sister, Pattie, got eight. Finally Jonah's older brother Chris walked into the same store. The clerk, having sensed the pattern, correctly guessed he would be wanting eleven.
What pattern did the clerk discern?
The shopkeeper knew for certain one thing you do not, but it's not a crucial detail