(753 x 753 + 247 x 247 - 753 x 247)/(753 x 753 x 753 + 247 x 247 x 247)=?
Select:
A) 1 / 1000
B) 1 / 506
C) 253 / 500
D) 253 / 1000
E) none of these

Rationale: given exp . = ( a ^ 2 + b ^ 2 - ab ) / ( a ^ 3 + b ^ 3 ) = 1 / ( a + b ) = 1 / ( 753 + 247 ) = 1 / 1000 answer : a
Answer: A