I've had some questions from students on the Venn Diagram examples and the Venn Diagram problems in the WebAssign homework. YouTube has a lot of examples that you'll find if you just search on "Venn Diagrams". And I've posted one additional new example in the Part 4 videos. Depending on how the data is organized in a question, Venn Diagram problems may be very straightforward, or they may require and little "sniffing around" and introducing some temporary variables to help figure out how all the missing pieces of information are related. So there's not really a one-size-fits-all approach. Basically, just look at all the information you have available and figure out how to put it in your picture. Then, if necessary, write down the relationships (i.e. the equations) that allow you to figure out the missing pieces.