Consider the following problem presented by Tversky and Kahneman (1983): Linda is 31 years old, single, outspoken, and very bright. She majored in philosophy. As a student, she was deeply concerned with issues of discrimination and social justice, and also participated in anti-nuclear demonstrations. Which is more probable?

1. Linda is a bank teller.

2. Linda is a bank teller and is active in the feminist movement.

Most people choose the second answer, but this is a so-called conjunction fallacy. Provide a formal argument why alternative two cannot be more likely than alternative one.