The radius of a wheel is $3.5 \, cm$. What is the distance (in $cm$) travelled by the wheel in $20$ revolutions?

$66 \text{ cm}^3$ of silver is drawn into a wire $1 \text{ mm}$ in diameter. The length of the wire in metres will be

The capacity of a tank,in the form of a cylinder,is $6160 \, m^3$. If the diameter of its base is $28 \, m$,find out the cost of painting its inner curved surface at the rate of ₹ $2.8$ per $m^2$. (Use $\pi = \frac{22}{7}$)

The radius of the base of a solid cone is $9\, cm$ and its height is $21\, cm$. It is cut into $3$ parts by two cuts which are parallel to its base. The cuts are at heights of $7\, cm$ and $14\, cm$ from the base respectively. What is the ratio of the curved surface areas of the top,middle,and bottom parts respectively?

The radius of the base of a hollow cone is $8\, cm$ and its height is $15\, cm$. $A$ sphere of the largest possible radius is placed inside the cone. What is the ratio of the radius of the base of the cone to the radius of the sphere?

$A$ large cube is formed from the material obtained by melting three smaller cubes of $3, 4$ and $5 \, cm$ side. What is the ratio of the total surface areas of the smaller cubes and the large cube?