2007 AMC 8 Problems/Problem 13
Problem
Sets and
, shown in the Venn diagram, have the same number of elements.
Their union has
elements and their intersection has
elements. Find
the number of elements in
.
![AMC8 2007 13.png](https://wiki-images.artofproblemsolving.com//0/0f/AMC8_2007_13.png)
Solution
Let be the number of elements in
and
.
Since the union is the sum of all elements in and
,
and and
have the same number of elements then,
.
The answer is