Conjunction Fallacy

Examine the following personality sketch:

@Bill is 34 years old. He is intelligent, but unimaginative, compulsive and generally lifeless. In school, he was strong in mathematics but weak in social studies and humanities.@

Which statement is more probable:

1. Bill is an accountant that plays jazz for a hobby, or
2. Bill plays jazz for a hobby?

From http://www.dcs.qmul.ac.uk/~norman/BBNs/Conjunction_Fallacy.htm 2006.08.15

Category.Mind