Curved surface area of a hemisphere $= \ldots \ldots \ldots$

The length, breadth, and height of a cuboid are $30 \, cm$, $20 \, cm$, and $15 \, cm$ respectively. Its volume is $\ldots \ldots \ldots \, cm^3$.

The surface area of a sphere with a radius of $5 \, cm$ is five times the curved surface area of a cone with a radius of $4 \, cm$. Find the height and volume of the cone (take $\pi = \frac{22}{7}$).

Find the total surface area of a cylinder with diameter $28 \text{ cm}$ and height $50 \text{ cm}$. (in $\text{cm}^2$)

The diameter of a solid hemisphere is $42\, cm.$ Find the curved surface area of a hemisphere (in $cm^2$).

The radius and height of a cylindrical coin are $1.4 \, cm$ and $0.1 \, cm$ respectively. $60$ such coins are stacked up to make a larger cylindrical pillar. Find the volume of this larger cylinder (in $cm^3$).