The value of $$\frac{(1.8)^3 - (1.2)^3}{(1.8)^2 + 2.16 + (1.2)^2}$$​ is:

Correct option is D

Given:
​$$\frac{(1.8)^3 - (1.2)^3}{(1.8)^2 + 2.16 + (1.2)^2} \\$$ 
Formula Used:
​$$\frac{a^3 - b^3}{a^2 + ab + b^2} = a - b \\$$ 
Solution:
​$$\Rightarrow \frac{(1.8)^3 - (1.2)^3}{(1.8)^2 + 2.16 + (1.2)^2} \\\Rightarrow \frac{(1.8)^3 - (1.2)^3}{(1.8)^2 +1.8 \times 1.2 + (1.2)^2} \\\text{Let } a = 1.8,\ b = 1.2 \\\text{Apply identity: } \frac{a^3 - b^3}{a^2 + ab + b^2} = a - b \\\Rightarrow a - b = 1.8 - 1.2 = 0.6 \\$$
The correct answer is 0.6​