Smallest Rectangle
Putnam Problem 1996:A1
http://www.reddit.com/r/learnmath/comments/22910t/1996_putnam_a1_help_understanding_solution/
Find the least number A such that for any two squares of combined area 1, a rectangle of area A exists such that the two squares can be packed in the rectangle (without interior overlap). You may assume that the sides of the squares are parallel to the sides of the rectangle.
Note: I changed it to sum of areas = 100 to make it a little more accessible.