Question Detail

The cube root of .000216 is

0.6
0.006
0.06
.0006

Answer: Option C

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. 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}

3. Evaluate
\begin{aligned} \sqrt[3]{4\frac{12}{125}} \end{aligned}

\begin{aligned} 1\frac{2}{5} \end{aligned}
\begin{aligned} 1\frac{3}{5} \end{aligned}
\begin{aligned} 1\frac{4}{5} \end{aligned}
1

Answer: Option B

Explanation:

\begin{aligned}
= \sqrt[3]{\frac{512}{125}} \end{aligned}
\begin{aligned}
= (\frac{8*8*8}{5*5*5})^{\frac{1}{3}} \end{aligned}

\begin{aligned} = \frac{8}{5} = 1\frac{3}{5} \end{aligned}

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

Answer: Option B

5. 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