If a/b + b/a = 1 , then the value of a3 + b3 will be?

Answer: Option B

$$\begin{array}{rl}& a^2+b^2=ab........(i)\\ & a^2+b^2-ab=0\\ & \because a^3+b^3=\left(a+b\right)\left(a^2+b^2-ab\right).....(ii)\\ & \text{From equation (i) and (ii)}\\ & \Rightarrow a^3+b^3=\left(a+b\right)\left(0\right)\\ & \Rightarrow a^3+b^3=0\end{array}$$