The question is really wrong. I've heard a similar question before and it goes more like this:
"A team of psychologists performed personality tests on 100 professionals, of which 5 were engineers and 95 were lawyers. Brief descriptions were written for each subject. The following is a randomly picked sample of one of the resulting descriptions:
'Jack is a 45-year old man who enjoys recreational Mathematics.'
Assume 90% of engineers enjoy recreational Mathematics and only 10% of lawyers do. What is the chance that Jack is an engineer?"
And the point is that the odds are still that Jack is a lawyer. The question as posed in the article, though, really doesn't make sense.
"A team of psychologists performed personality tests on 100 professionals, of which 5 were engineers and 95 were lawyers. Brief descriptions were written for each subject. The following is a randomly picked sample of one of the resulting descriptions: 'Jack is a 45-year old man who enjoys recreational Mathematics.' Assume 90% of engineers enjoy recreational Mathematics and only 10% of lawyers do. What is the chance that Jack is an engineer?"
And the point is that the odds are still that Jack is a lawyer. The question as posed in the article, though, really doesn't make sense.