Independence on Venn diagrams

A synthetic classification records two properties for each sample message

Let \(A\) be the set of items classified as unread, and let \(B\) be the set of items classified as attached

The sample space \(S\) contains 18 items

\(S = \{1\), \(2\), \(3\), \(4\), \(5\), \(6\), \(7\), \(8\), \(9\), \(10\), \(11\), \(12\), \(13\), \(14\), \(15\), \(16\), \(17\), \(18\}\)

\(A = \{1\), \(2\), \(3\), \(5\), \(6\), \(7\), \(10\), \(11\), \(12\), \(13\), \(15\), \(16\}\)

\(B = \{2\), \(5\), \(10\), \(12\), \(14\), \(15\), \(17\}\)

Numbers in the Venn diagram show how many items are in each region, not the item numbers

One item is selected uniformly at random from S; every item has the same chance of selection