Suppose Set B contains 382 elements and the total number elements in either Set A or Set B is 625. If the Sets A and B have 86 elements in common, how many elements are contained in set A?

Answer 1

Draw a Venn Diagram (two intersecting circles with one circle labeled A and the other circle labeled B)

There are 3 regions. The intersection of A and B contains 86 elements. The portion of circle B that doesn't intersect circle A contains 382 - 86 = 296 elements. So, the number of elements in A that are not in B is

625 - 86 - 296 = 243. Therefore, the number of elements in A is 243 + 86 = 329