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

If the area of the base,height,and volume of a right prism are $(3 \sqrt{3} / 2) P^{2} \, \text{cm}^{2}$,$100 \sqrt{3} \, \text{cm}$,and $7200 \, \text{cm}^{3}$ respectively,then the value of $P$ is?

The capacity of a cylindrical tank is $246.4$ litres. If the height is $4$ metres,what is the diameter of the base? (in $m$)

How many bricks,each measuring $25\, cm \times 11.25\, cm \times 6\, cm$,will be needed to build a wall $8\, m \times 6\, m \times 22.5\, cm$?

$A$ rectangular plot,$36 \, m$ long and $28 \, m$ broad,has two concrete roads $5 \, m$ wide running in the middle of the park,one parallel to the length and the other parallel to the breadth. What would be the total cost of gravelling the plot,excluding the area covered by the roads,at ₹ $3.60$ per $m^{2}$? (in $Rs.$)

$A$ circular wire of radius $42 \, cm$ is cut and bent in the form of a rectangle whose sides are in the ratio $6:5$. Find the smaller side of the rectangle (in $cm$).