I spent 10 minutes (cuz long query times) trying to figure out how to join tables to get results for only Jon and Mike, just to find out there is noone else... -___-

Personally I find this description kinda confusing.
'Nathan drinks 0.5 liter every 1 hour.'
This way it makes no sense that for 11h he drank 5l instead of 5.5l.
It's more like he drinks 1l every 2h.

I know it's about semantics, but in my case it made this simple kata hard, cuz I rounded wrong thing to smalles number as it matched the description better in my eyes.

Thank you very much for your help <3
It indeed works if I put first condition in the same line as return.