$$\begin{aligned} \sqrt{41 - \sqrt{21 + \sqrt{19 - \sqrt{9}}}} \end{aligned}$$

Answer: Option D

Explanation:

$$\begin{aligned} = \sqrt{41 - \sqrt{21 + \sqrt{19 - 3}}} \end{aligned}$$

$$\begin{aligned} = \sqrt{41 - \sqrt{21 + \sqrt{16}}} \end{aligned}$$

$$\begin{aligned} = \sqrt{41 - \sqrt{21 + 4}} \end{aligned}$$

$$\begin{aligned} = \sqrt{41 - \sqrt{25}} \end{aligned}$$

$$\begin{aligned} = \sqrt{41 - \sqrt{25}} \end{aligned}$$

$$\begin{aligned} = \sqrt{41 - 5} \end{aligned}$$

$$\begin{aligned} = \sqrt{36} = 6 \end{aligned}$$

Answer: Option C

Explanation:

$$\begin{aligned} = \sqrt{248+\sqrt{64}} \end{aligned}$$

$$\begin{aligned} = \sqrt{248+8} \end{aligned}$$

$$\begin{aligned} = \sqrt{256} \end{aligned}$$

$$\begin{aligned} = 16 \end{aligned}$$

Answer: Option A

Explanation:

as .4 * .4 = 0.16

Answer: Option D

Explanation:

$$\begin{aligned} = \sqrt{.000064} \end{aligned}$$
$$\begin{aligned} = \sqrt{\frac{64}{10^6}} \end{aligned}$$
$$\begin{aligned} = \frac{8}{10^3} = .008 \end{aligned}$$
$$\begin{aligned} = \sqrt[3]{.008} \end{aligned}$$
$$\begin{aligned} = \sqrt[3]{\frac{8}{1000}} \end{aligned}$$
$$\begin{aligned} = \frac{2}{10} = 0.2 \end{aligned}$$

Answer: Option C