The surface area of a sphere is $7850 \, cm^2$. Find its radius in $cm$. (Use $\pi = 3.14$)

The ratio of the radius and slant height of a cone is $3:5$ and its curved surface area is $423.9 \, cm^2$. Find its volume. $(\pi = 3.14)$ (in $cm^3$)

The radius of the base of a cone is $7 \, cm$ and its height is $30 \, cm$. Find the volume of a cone (in $cm^3$).

The areas of the three surfaces meeting at one vertex of a cuboid are $700 \, cm^2$,$300 \, cm^2$,and $525 \, cm^2$ respectively. Find the dimensions and volume of the cuboid.

The radius and the slant height of a cone are in the ratio $4: 7$. The ratio of its total surface area to its curved surface area is $\ldots \ldots \ldots$

The total surface area of a cone whose radius is $\frac{r}{2}$ and slant height is $2l$ is