Find the volume of a sphere whose surface area is $154 \, cm^2$.

The pillars of a temple are cylindrically shaped (see Fig.). If each pillar has a circular base of radius $20\, cm$ and height $10\, m$,how much concrete mixture would be required to build $14$ such pillars (in $, m^3$)?

$A$ matchbox measures $4 \,cm \times 2.5 \,cm \times 1.5 \,cm.$ What will be the volume of a packet containing $12$ such boxes (in $,cm^3$)?

The volume of a right circular cone is $9856 \, cm^3$. If the diameter of the base is $28 \, cm$,find the slant height of the cone. (in $, cm$)

The length,breadth,and height of a room are $5\, m$,$4\, m$,and $3\, m$ respectively. Find the cost of whitewashing the walls of the room and the ceiling at the rate of $Rs. 7.50$ per $m^2$.

$A$ wooden bookshelf has external dimensions as follows: Height $= 110\, cm$,Depth $= 25\, cm$,Breadth $= 85\, cm$ (see Fig.). The thickness of the plank is $5\, cm$ everywhere. The external faces are to be polished and the inner faces are to be painted. If the rate of polishing is $20$ paise per $cm^2$ and the rate of painting is $10$ paise per $cm^2$,find the total expenses required for polishing and painting the surface of the bookshelf.