If a = 355, b = 356, c = 357,then find the value of $$a^3 + b^3 + c^3 - 3abc$$.

Given, $$a$$ = 355, $$b$$ = 356, $$c$$ = 357

$$a^3+b^3+c^3—3abc=\left(a+b+c\right)\left(a^2+b^2+c^2-ab-bc-ca\right)$$

$$=\frac{1}{2}\left(a+b+c\right)\left(2a^2+2b^2+2c^2-2ab-2bc-2ca\right)$$

$$=\frac{\left(a+b+c\right)}{2}\left[\left(a-b\right)^2+\left(b-c\right)^2+\left(c-a\right)^2\right]$$

$$=\frac{\left(355+356+357\right)}{2}\left[\left(355-356\right)^2+\left(356-357\right)^2+\left(357-355\right)^2\right]$$

$$=\frac{1068}{2}\left[1+1+4\right]$$

$$=\frac{1068}{2}\left[6\right]$$

$$=3204$$

Hence, the correct answer is Option A