R. D. Sharma Solutions for Chapter: Mensuration-II (Volumes and Surface Areas of a Cuboid and a Cube), Exercise 3: EXERCISE

If the area of the cardboard is $k {\mathrm{cm}}^2$ to make a closed box of length $25 \mathrm{c}\mathrm{m}, 0.5 \mathrm{m}$ and height $15 \mathrm{c}\mathrm{m}$. Find the value of $k$.

If the surface area of a wooden box is $k {\mathrm{cm}}^2$, whose shape is of a cube, and if the edge of the box is $12 \mathrm{c}\mathrm{m}$ then find $k$.

A classroom is $11 \mathrm{m}$ long, $8 \mathrm{m}$ wide and $5 \mathrm{m}$ high. And the sum of the areas of its floor and the four walls (including doors, windows, etc.) is $k {\mathrm{m}}^2$, find the value of $k$.

A swimming pool is $20 \mathrm{m}$ long $15 \mathrm{m}$ wide and $3 \mathrm{m}$ deep. Find the cost of repairing the floor and wall at the rate of $₹ 25$ per square metre.

The walls and ceiling of a room are to be plastered. The length, breadth and height of the room are $4.5 \mathrm{m}, 3 \mathrm{m}$ and $350 \mathrm{c}\mathrm{m}$, respectively. Find the cost of plastering at the rate of $₹ 8$ per square meter.

A cuboid has total surface area of $50 {\mathrm{m}}^2$ and lateral surface area is $30 {\mathrm{m}}^2$. If the area of its base is $k {\mathrm{m}}^2$ what is the value of $k$.

A classroom is $7 \mathrm{m}$ long. $6 \mathrm{m}$ broad and $3.5 \mathrm{m}$ high. Doors and windows occupy an area of $17 {\mathrm{m}}^2$. What is the cost of white-washing the walls at the rate of $₹1.50$ per ${\mathrm{m}}^2$.

The central hall of a school is $80 \mathrm{m}$ long and $8 \mathrm{m}$ high. It has $10$ doors each of size $3 \mathrm{m}\times 1.5 \mathrm{m}$ and $10$ windows each of size $1.5 \mathrm{m}\times 1 \mathrm{m}$. If the cost of white-washing the walls of the hall at the rate of $₹ 1.20$ per ${\mathrm{m}}^2$ is $₹ 2385.60$, find the breadth of the hall.