Numbers - General Aptitude

Q1:

854 x 854 x 854 - 276 x 276 x 276 = ?
854 x 854 + 854 x 276 + 276 x 276

A 1130

B 578

C 565

D 1156

E None of these

ANS:B - 578

Given Exp. = (a3 - b3) = (a - b) = (854 - 276) = 578
(a2 + ab + b2)