Question

Which of the following is a counterexample to the statement “All freshman girls are going to the dance”?

A. Robert, a freshman boy, is going to the dance.

B. Julia, a junior girl, is not going to the dance.

C. Roberta, a freshman girl, is not going to the dance.

D. All sophomore girls are not going to the dance.

Answer 1

A counterexample is an example which opposes an idea. The idea that all freshman girls are going to the dance can be opposed by saying that one of them will not be going. If one out of a group does not go to the dance, then the statement that all of these girl types are going would be a false statement. Most of the freshman girls will be going, aside from one. Roberta is causing problems for this statement. You'd better tell her to straighten her act up!