The radius of a cylinder is increased by $20 \%$,keeping its height unchanged. What is the percentage increase in its volume?

$A$ tank $3\, m$ long,$2\, m$ wide and $1.5\, m$ deep is dug in a field $22\, m$ long and $14\, m$ wide. If the earth dug out is evenly spread out over the field,the level of the field will rise by nearly (in $cm$)

The heights of a cone,cylinder,and hemisphere are equal. If their radii are in the ratio $2: 3: 1$,then the ratio of their volumes is

$A$ $12\,m$ deep well with internal diameter $3.5\,m$ is dug. The earth taken out from it is spread evenly to form a platform of dimensions $10.5\,m \times 8.8\,m$. Determine the height of the platform in meters. (in $.25$)

Calculate the number of bricks,each measuring $25 \, cm \times 15 \, cm \times 8 \, cm$,required to construct a wall with dimensions $19 \, m \times 4 \, m \times 5 \, m$,when $10 \%$ of its volume is occupied by mortar.

$3$ solid cubes whose edges are $6, 8$ and $10 \, cm$ respectively,are melted and formed into a single cube. If there is no loss of metal in the process,find the edge of the new cube (in $cm$).