Volume of a sphere

Q. Question 1
Metal spheres, each of radius 2 cm, are packed into a rectangular box of internal dimensions $16cm\times 8cm\times 8cm$. when 16 spheres are packed the box is filled with preservative liquid. Find the volume of this liquid. Give your answer to the nearest integer. $[use\pi =3.14]$

Q. If the ratio of volume to total surface area of a solid sphere is 8:1, then the radius of the sphere is units.

1. 24
2. 8
3. 16
4. 20

Q. What is the formula for the volume of a sphere?

1. $V=3\pi r$
2. $V=\frac{4}{3}\pi r^3$
3. $V=\frac{2}{3}\pi r^2$
4. $V=2\pi r^2$

Q.

An iron spherical ball of radius 21cm is melted and it is re-casted in hemispheres of radius 7cm. The number of hemispherical balls formed will be

___

Q. If the volume of a sphere is $38808{cm}^3$ then its radius is = ___ cm.

Q. The radius of the two solids used to make the ladders is the same, i.e. 6 ft. What is the total volume used to make the two ladders?

1. $828\pi$ ft${}^3$
2. $628\pi$ ft${}^3$
3. $540\pi$ ft${}^3$
4. $880\pi$ ft${}^3$