1. The problem statement, all variables and given/known data There are three two-dimensional graphs and asked about their divisibility, additivity, and convexity qualities. I know how to distinguish convexity - when all the points on the straight line between any two points of the set are also contained in the set. But I have been struggling to understand how to recognize graph's divisibility and additivity. Divisibility implies that goods are infinitely divisible. Additivity means that it's possible to add consumption bundles. Can you help please? Graphs are attached.