Find the value of X
\begin{aligned} \sqrt{81} + \sqrt{0.81} = 10.09 - X \end{aligned}

Answer: Option B

Explanation:

\begin{aligned}
=> \sqrt{81} + \sqrt{0.81} = 10.09 - X
\end{aligned}

\begin{aligned}
=> 9 + 0.9 = 10.09 - X
\end{aligned}

\begin{aligned}
=> X = 10.09 - 9.9 = 0.19
\end{aligned}

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 D

Answer: Option D

Explanation:

Tip: Please check the question carefully before answering. As 3a is not under the root we can convert it into a formula , lets evaluate now :

\begin{aligned}
= \sqrt{4a^2 - 4a + 1} + 3a \end{aligned}

\begin{aligned}
= \sqrt{(1)^2 + (2a)^2 - 2x1x2a} + 3a \end{aligned}

\begin{aligned}
= \sqrt{(1-2a)^2} + 3a \end{aligned}

\begin{aligned}
= (1-2a) + 3a \end{aligned}

\begin{aligned}
= (1-2a) + 3a \end{aligned}

\begin{aligned}
= 1 + a = 1 + 0.1039 = 1.1039 \end{aligned}

Answer: Option D

Explanation:

L.C.M. of 21, 36, 66 = 2772

Now, 2772 = 2 x 2 x 3 x 3 x 7 x 11

To make it a perfect square, it must be multiplied by 7 x 11.

So, required number = 2 x 2 x 3 x 3 x 7 x 7 x 11 x 11 = 213444