If 3 5 + 125 = 17.88, then what will be the value of 80 + 6 5 \,\,?

Answer: Option D

$$\begin{array}{rl}& 3\sqrt{5}+\sqrt{125}=17.88\\ & \Rightarrow 3\sqrt{5}+\sqrt{25\times 5}=17.88\\ & \Rightarrow 3\sqrt{5}+5\sqrt{5}=17.88\\ & \Rightarrow 8\sqrt{5}=17.88\\ & \Rightarrow \sqrt{5}=2.235\\ & \therefore \sqrt{80}+6\sqrt{5}=\sqrt{16\times 5}+6\sqrt{5}\\ & =4\sqrt{5}+6\sqrt{5}\\ & =10\sqrt{5}=\left(10\times 2.235\right)=22.35\end{array}$$