Question : If the inner radius of a hemispherical bowl is 5 cm and its thickness is 0.25 cm, find the volume of the material required to make the bowl. (Use $\pi = \frac{22}{7}$)
(Rounded up to two decimal places).

Question : The length of a side of an equilateral triangle is 8 cm. The area of the region lying between the circumcircle and the incircle of the triangle is __________ ( Use: $\pi = \frac{22}{7}$)

Question : The radii of the ends of a frustum of a cone 7 cm high are 5 cm and 3 cm. Find its volume correct to one decimal place. (Use $\pi=\frac{22}{7}$)

Question : The volume of a sphere of radius 4.2 cm is: (Use $\pi=\frac{22}{7}$)

Question : Find the length of the arc of the sector of a circle of diameter 7 cm with a central angle of $108^{\circ}$. [Use $\pi=\frac{22}{7}$]