If the volume of a sphere is numerically equal to its surface area,then its diameter is ......... $cm$.

If each edge of a cube is increased by $50 \%$,the percentage increase in surface area is (in $\%$)

The ratio of total surface area to lateral surface area of a cylinder whose radius is $80 \text{ cm}$ and height $20 \text{ cm}$ is: (in $:1$)

The radius and height of a right circular cone are in the ratio $5:12$. If its volume is $314 \frac{3}{7} \text{ m}^3$,find the radius of the cone (in $\text{m}$).

If the radius of a sphere is doubled,then its volume is increased by (in $\%$)

Two $cm$ of rain has fallen on a square $Km$ of land. Assuming that $50 \%$ of the raindrops could have been collected and contained in a pool having a $100 \, m \times 10 \, m$ base,by what level would the water level in the pool have increased?