Find the cube-roots of -175616

$64\sqrt{x^6}$ - $\sqrt{64 \times x^6}$ is equal to :

1. 72x³

2. 56x²

3. 128x³

4. 56x³

Two numbers are in the ratio 5 : 4. If the difference of their cubes is 61; the numbers are :

1. 5 and 4

2. 25 and 16

3. 10 and 18

4. none of these

The value of $\sqrt[3]{27} + \sqrt[3]{0.008} + \sqrt[3]{0.064}$ is :

1. $\sqrt[3]{27.072}$

2. 3.72

3. 3.6

4. 3.06