Tourist is related to City. you are likely to find Bar in/at/on City. Bar is related to Party. 
you are likely to find Number in/at/on Equation. Minority is a type of Number. Minority is a type of Age. 
Tourist <--RelatedTo--> City <--AtLocation-- Bar <--RelatedTo--> Party 
Equation <--AtLocation-- Number <--IsA-- Minority --IsA--> Age 