Thanks for the reply, but I doubt that the issue surrounds (ab)use of the word "accountant". If you go to the attributed source (at http://www.reddit.com/r/math

Thanks for the reply, but I doubt that the issue surrounds (ab)use of the word "accountant". If you go to the attributed source (at http://www.reddit.com/r/math/comments/12n04d/counterintuitive_mathematical_results_accessible/c6wion3 http://www.reddit.com/r/math/comments/12n04d/counterintuitiv...), instead of water-heater/accountant/plumber it's car/teacher/mechanic. I'm more inclined to believe this is a (poor) illustration of the idea that a sub-set is likely to be smaller than the set it came from: the set of all accountants vs. the sub-set of all accountants who are also plumbers. In which case - duh! - P(accountant) > P(accountant and plumber). As long as one can indulge in the naivety of this pedagogical tale, that the narrator (the "I" who said "I went to a person") wasn't too particular on whom he hired for the job, then sure, why not?, 'twas likely the accountant that fixed it. In the real world, which has teachers and mechanics in addition to accountants and plumbers and other occupations, and where people may tend to be pickier on who they'll let near their water heater - leave alone pay someone to mess with it - would this conclusion of "accountant" still prevail necessarily?