Question Detail

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

0.019
0.19
0.9
0.109

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}

1. The largest four digit number which is a perfect cube, is:

7000
8000
9261
9999

Answer: Option C

Explanation:

21*21*21 = 9261

2. The least perfect square, which is divisible by each of 21, 36 and 66 is

213414
213424
213434
213444

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

3. \begin{aligned} \sqrt{\frac{32.4}{x}} = 2 \end{aligned}

Answer: Option B

4. \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}