This blog is the disorganized ramblings of College-Prep Tutor Phillip McCaffrey, who loves to help high school students beat the SAT, ACT and any other test for that matter [because tests don't REALLY matter in the long run].
SAT Venn Diagram, systems of equations
In a survey of 200 pet owners, each person has a dog or a cat or both. If there are 180 dog owners and 160 cat owners. How many of the cat owners have no dogs?