The base of a $10\, cm$ high solid cylinder is a semi-circle of radius $7\, cm$. Its total surface area (in $cm^2$) is (Use $\pi = \frac{22}{7}$)

$A$ reservoir, $30\, m$ long and $15\, m$ broad, is filled with water. How many gallons of water must be taken out to lower the level of water by $4\, m$? (in gallons)

$A$ solid cylinder having a radius of base as $7 \, cm$ and length as $20 \, cm$ is bisected along its height to get two identical cylinders. What will be the percentage increase in the total surface area?

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 $\pi = \frac{22}{7}$)

$A$ solid metallic spherical ball of diameter $6\, cm$ is melted and recast into a cone with diameter of the base as $12\, cm$. The height of the cone is........$cm$

$A$ solid consists of a circular cylinder with an exact fitting right circular cone placed on the top. The height of the cone is $h$. If the total volume of the solid is three times the volume of the cone,then the height of the cylinder is