R. D. Sharma Solutions for Chapter: Surface Area and Volume of a Cuboid and Cube, Exercise 1: EXERCISE

Each edge of a cube is increased by $50\%$. Find the percentage increase in the surface area of the cube.

A closed iron tank $12 \mathrm{m}$ long, $9 \mathrm{m}$ wide and $4 \mathrm{m}$ deep is to be made. Determine the cost of iron sheet used at the rate of $₹ 5$ per metre sheet, sheet being $2 \mathrm{m}$ wide.

Ravish wanted to make a temporary shelter for his car by making a box-like structure with tarpaulin that covers all the four sides and the top of the car ( with the front face as a flap which can be rolled up). Assuming that the stitching margins are very small, and therefore negligible, to make the shelter of height $2.5 \mathrm{m}$ with base dimensions $4 \mathrm{m}\times 3 \mathrm{m}$ tarpaulin would be required$=$_____${\mathrm{m}}^2$.

An open box is made of wood $3 \mathrm{cm}$ thick. Its external length, breadth and height are $1.48 \mathrm{m}, 1.16 \mathrm{m}$ and $8.3 \mathrm{dm}$. Find the cost of painting the inner surface of $₹ 50$ per sq- meter.

The dimensions of a room are $12.5 \mathrm{m}$ by $9 \mathrm{m}$ by $7 \mathrm{m}$. There are $2$ doors and $4$ windows in the room; each door measures $2.5 \mathrm{m}$ by $1.2 \mathrm{m}$ and each window $1.5 \mathrm{m}$ by $1 \mathrm{m}$. Find the cost of painting the walls at $₹ 3.50$ per square meter.

The paint in a certain container is sufficient to paint on area equal to $9.375 {\mathrm{m}}^2$, How many bricks of dimension $22.5 \mathrm{cm}\times 10 \mathrm{cm}\times 7.5 \mathrm{cm}$ can be painted out of this container?

The cost of preparing the walls of a room $12 \mathrm{m}$ long at the rate of $₹ 1.35$ per square meter is $₹ 340.20$ and the cost of matting the floor at 85 paisa per square meter is $₹ 91.80$. Find the height of the room.

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