A solid metal sphere of $6 \mathrm{cm}$ diameter is melted and a circular sheet of thickness $1 \mathrm{cm}$ is prepared. Determine the diameter of the sheet.

An iron pillar consists of a cylindrical portion $2.8 \mathrm{m}$ high and $20 \mathrm{cm}$ in diameter and a cone $42 \mathrm{cm}$ high is surmounting it. Find the weight of the pillar, given that $1$ cubic $\mathrm{cm}$ of iron weighs $7.5 \mathrm{gm}$. If the weight of the pillar is $\mathrm{x} \mathrm{kg}$ then find $\mathrm{x}$. $(\mathrm{Take} \mathrm{\pi }=22/7)$

Height of a solid cylinder is $10 \mathrm{cm}$ and diameter $8 \mathrm{cm}$. The diameter of the holes is $6 \mathrm{cm}$ and height $4 \mathrm{cm}$. If the volume of the cylinder is $\mathrm{k\pi } {\mathrm{cm}}^3$, then find the value of $\mathrm{k}$. 

Height of a solid cylinder is $10 \mathrm{cm}$ and diameter $8 \mathrm{cm}$. Two equal conical hole have been made from its both ends. The diameter of the holes is $6 \mathrm{cm}$ and height $4 \mathrm{cm}$. If volume of one conical hole is $\mathrm{k\pi } {\mathrm{cm}}^3$, find the value of $\mathrm{k}$.

Height of a solid cylinder is $10 \mathrm{cm}$ and diameter $8 \mathrm{cm}$. Two equal conical hole have been made from its both ends. If the diameter of the holes is $6 \mathrm{cm}$ and the height $4 \mathrm{cm}$, If volume of  remaining solid is $\mathrm{k\pi } {\mathrm{cm}}^3$, find the value of $\mathrm{k}$.