J P Mohindru and Bharat Mohindru Solutions for Chapter: Surface Areas and Volumes, Exercise 3: EXERCISE

A container, open at the top, is in the form of a frustum of cone of height $24 \mathrm{cm}$ with radii of its lower and upper circular ends as $8 \mathrm{cm}$ and $20 \mathrm{cm}$ respectively.  Find the cost of the milk which can completely fill the container, at the rate of $₹21$ per litre.  Express the answer rounded off to the closest rupee.  $\left(\mathrm{Use} \mathrm{\pi }=\frac{22}{7}\right)$

A container, open at the top and made up of metal sheet, is in the form of a frustum of a cone of height $16 \mathrm{cm}$ with diameters of its lower and upper ends as $16 \mathrm{cm}$ and $40 \mathrm{cm}$ respectively.  Find the cost of the metal sheet used to make the container, if it costs $₹10$ per $100 {\mathrm{cm}}^2$.  Express the answer rounded off to the closest rupee.  $\left(\mathrm{Use} \mathrm{\pi }=\frac{22}{7}\right)$

A bucket is in the form of a frustum of a cone with a capacity of $1208.8 {\mathrm{cm}}^3$ of water. The radii of the top and bottom circular ends are $20 \mathrm{cm}$ and $12 \mathrm{cm}$ respectively. Find the height of the bucket and the area of the metal sheet used in its making.

Note: The above question has a wrong data and the correct question is mentioned as below.

A bucket is in the form of a frustum of a cone with a capacity of $12308.8 {\mathrm{cm}}^3$of water. The radii of the top and bottom circular ends are $20 \mathrm{cm}$ and $12 \mathrm{cm}$ respectively. Find the height of the bucket and the area of the metal sheet used in its making. Use $\mathrm{\pi }=3.14$

A bucket made of aluminium sheet ,is height $20 \mathrm{cm}$ and its radii of upper and lower ends are of $25 \mathrm{cm}$and $10 \mathrm{cm}$respectively. Find the cost of making the bucket if the aluminium sheet costs $₹70$ per $100 {\mathrm{cm}}^2$ (Use $\mathrm{\pi }=3.14$)

The radii of its circular ends of a solid frustum of a cone are $33 \mathrm{cm}$ and $27 \mathrm{cm}$ and its slant height is $10 \mathrm{cm}$. If its total surface area is$k {\mathrm{cm}}^2$, find $k$ (upto two decimal places).(Take $\mathrm{\pi }=\frac{22}{7}$ )

A solid is in the shape of frustum of a cone. The diameters of the two circular ends are $60 \mathrm{cm}$ and $36 \mathrm{cm}$ and the height is $9 \mathrm{cm}$. Find the area of its whole surface and the volume.

A milk container is made of metal sheet in the shape of frustum of a cone whose volume is $10459\frac{3}{7} {\mathrm{cm}}^3$. The radii of its lower and upper circular ends are $8 \mathrm{cm}$ and $20 \mathrm{cm}$ respectively. Find the cost of metal sheet used in making the container at the rate of $₹1.40$ per ${\mathrm{cm}}^2$.

In Fig.,from the  top of a solid cone of height $12 \mathrm{cm}$ and base radius $6 \mathrm{cm}$, a cone of height $4 \mathrm{cm}$ is removed by a plane parallel to the base. If the total surface area of the remaining solid is $k {\mathrm{cm}}^2$, find $k$ (upto two decimal places) (Use $\mathrm{\pi }=\frac{22}{7}$ and $\sqrt{5}=2.236$)