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 $m^2$.

Monica has a piece of canvas whose area is $551 \, m^2$. She uses it to have a conical tent made,with a base radius of $7 \, m$. Assuming that all the stitching margins and the wastage incurred while cutting amounts to approximately $1 \, m^2$,find the volume of the tent that can be made with it. (in $, m^3$)

The radii of two cylinders are in the ratio $3: 7$ and their heights are in the ratio $28: 15$. Calculate the ratio of their curved surface areas.

The diameter of a solid hemisphere is $7 \, cm$. Find its curved surface area and total surface area (in $cm^2$).

Find the total surface area of a hemisphere of radius $10 \, cm.$ (Use $\pi = 3.14$) (in $cm^2$)

$A$ square sheet of paper,$44 \, cm$ long,is rolled along its length to form a cylinder. Find the volume of the cylinder so formed. (in $cm^3$)