Question Detail

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

1. Evaluate \begin{aligned}
\sqrt{1471369}
\end{aligned}

1213
1223
1233
1243

Answer: Option A

2. What is the smallest number by which 3600 be divided to make it a perfect cube.

Answer: Option A

Explanation:

\begin{aligned}
3600 = 2^3 \times 5^2 \times 3^2 \times 2
\end{aligned}
To make it a perfect cube it must be divided by
\begin{aligned}
5^2 \times 3^2 \times 2 = 450
\end{aligned}

3. Evaluate \begin{aligned} \sqrt[3]{\sqrt{.000064}} \end{aligned}

0.0002
0.002
0.02
0.2

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}

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

Answer: Option B

5. Evaluate
\begin{aligned}
\sqrt{10+\sqrt{25+\sqrt{108+\sqrt{154+\sqrt{225}}}}}
\end{aligned}

Answer: Option D

Explanation:

\begin{aligned}
= \sqrt{10+\sqrt{25+\sqrt{108+\sqrt{154+\sqrt{225}}}}}
\end{aligned}

\begin{aligned}
=\sqrt{10+\sqrt{25+\sqrt{108+\sqrt{154+15}}}}
\end{aligned}

\begin{aligned}
=\sqrt{10+\sqrt{25+\sqrt{108+\sqrt{154+15}}}}
\end{aligned}

\begin{aligned}
=\sqrt{10+\sqrt{25+\sqrt{108+\sqrt{169}}}}
\end{aligned}

\begin{aligned}
=\sqrt{10+\sqrt{25+\sqrt{108+13}}}
\end{aligned}

\begin{aligned}
=\sqrt{10+\sqrt{25+\sqrt{121}}}
\end{aligned}

\begin{aligned}
=\sqrt{10+\sqrt{25+11}}
\end{aligned}

\begin{aligned}
=\sqrt{10+\sqrt{36}}
\end{aligned}

\begin{aligned}
=\sqrt{10+6}
\end{aligned}

\begin{aligned}
=\sqrt{16} = 4
\end{aligned}

Question Detail

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

1. Evaluate \begin{aligned} \sqrt{1471369} \end{aligned}

2. What is the smallest number by which 3600 be divided to make it a perfect cube.

3. Evaluate \begin{aligned} \sqrt[3]{\sqrt{.000064}} \end{aligned}

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

5. Evaluate \begin{aligned} \sqrt{10+\sqrt{25+\sqrt{108+\sqrt{154+\sqrt{225}}}}} \end{aligned}

1. Evaluate \begin{aligned}
\sqrt{1471369}
\end{aligned}

5. Evaluate
\begin{aligned}
\sqrt{10+\sqrt{25+\sqrt{108+\sqrt{154+\sqrt{225}}}}}
\end{aligned}