Find the surface area and volume of a sphere of diameter $28 \, cm$.

$A$ cube of side $4 \, cm$ contains a sphere touching its sides. Find the volume of the gap in between. (in $, cm^3$)

Find the curved surface area and the total surface area of a hemisphere with a diameter of $126 \, cm$.

The radius and volume of a cylinder are $3.5\,cm$ and $2310\,cm^3$ respectively. Find its height in $cm$.

$A$ cylindrical tube open at both ends is made of an iron sheet which is $2 \, cm$ thick. If the outer diameter is $16 \, cm$ and its length is $100 \, cm$, find how many cubic centimeters of iron have been used in making the tube? (in $cm^3$)

The radius and slant height of a cone are in the ratio of $5:13$. If its curved surface area is $1836.9 \, cm^2$,find its volume. (Use $\pi = 3.14$) (in $cm^3$)