Evan,

>Here's a fun one. http://www.boingboing.net/2005/08/24/puzzle_of_the_month_.html

This is the entire universe of possibilities (assuming integer ages)

a      1       1     225
b      1       3      75
c      1       5      45
d      1       9      25
e      1      15      15
f      3       3      25
g      3       5      15
h      5       5       9

a can be eliminated because 225 is an impossible age to attain. e g and h can be eliminated because the oldest person is not of legal age to own a home. f could be eliminated because it sums to the same value as e. But I don't see any way to eliminate down to only one of the remaining b, c and d candidate solutions.