If a 7 cm cube is cut into 1 cm cubes, then what is the percentage increase in the surface area of the resulting cubes?	Choices:
A) 140 % B) 350 % C) 450 % D) 600 % E) 700 %

Rationale: the area a of the large cube is 7 * 7 * 6 = 294 square cm . the area of the 343 small cubes is 7 * 7 * 7 * 6 = 7 a , an increase of 600 % . the answer is d .
Answer: D