A company seeks to hire engineering graduates who also speak a foreign language. Should you describe the combination of talents as an intersection or a union? Customers visit a store with several...

A company seeks to hire engineering graduates who also speak a foreign language. Should you describe the combination of talents as an intersection or a union?

Customers visit a store with several departments. A randomly chosen customer goes to the sporting goods department. After wandering for a bit, she buys a pair of running shoes. This event is most naturally viewed as which, a union or an intersection?