probability and venn diagrams

P(A) means the probability that a randomly picked person (from the entirety) is in set A

= n(A)/n(E)

conditional probability and venn diagrams

a ppt is here

requires some fore-understanding of venn diagrams
solutions can be simplified to a nice fraction (even though they don't need to be)

reasonably obvious 'geometry' but this can also be approached with a simple equation

probably better left to students to devise...