Given 2 = 1.414. Then the value of 8 + 2 32 - 3 128 + 4 50 is = ?

Answer: Option B

Given expression,
$$\sqrt{4\times 2}+2\sqrt{16\times 2}-3\sqrt{64\times 2}$$       $$+$$ $$4\sqrt{25\times 2}$$
$$\begin{array}{rl}& =2\sqrt{2}+8\sqrt{2}-24\sqrt{2}+20\sqrt{2}\\ & =6\sqrt{2}\\ & =6\times 1.414\\ & =8.484\end{array}$$