Jitender Gupta and Divya Malik Solutions for Exercise 3: Topic Exercise

The difference of the surface areas of two spheres is $3080 {\mathrm{cm}}^2$. If the radius of the larger sphere is $21 \mathrm{cm}$, then find the difference of their volumes.

If radius of a hemisphere be $42 \mathrm{cm}$, then find its curved surface area in ${\mathrm{cm}}^2$. Use $\mathrm{\pi }=\frac{22}{7}$

If radius of a hemisphere be $42 \mathrm{cm}$, then find its total surface area.

If radius of a hemisphere be $42 \mathrm{cm}$, then find its volume.

The radius of a hemispherical balloon increases from $6 \mathrm{cm}$ to $12 \mathrm{cm}$ as air is being pumped into it. Find ratio of the surface areas of the balloon in the two cases.

A hemispherical bowl is made of steel, $0.25 \mathrm{cm}$ thick. The inner radius of the bowl is $5 \mathrm{cm}$. Find the outer curved surface area of the bowl. [Take $\mathrm{\pi }=\frac{22}{7}$]

A solid sphere and a solid hemisphere have the same total surface areas. Find the ratio of their volumes

The internal and external diameters of a hollow hemispherical vessel are $14 \mathrm{cm} \& 21 \mathrm{cm}$, respectively. The cost of silver plating of $1 {\mathrm{cm}}^2$ of the surface is$₹ 0.40$. Find the total cost of silver plating the vessel all over. [Take $\mathrm{\pi }=3.14$]