$1496 \, cm^3$ of a metal is used to cast a pipe of length $28 \, cm$. If the internal radius of the pipe is $8 \, cm$,then the outer radius of the pipe is (in $cm$):

The base of a $10\, cm$ high solid cylinder is a semi-circle of radius $7\, cm$. Its total surface area (in $cm^2$) is (Use $\pi = \frac{22}{7}$)

$A$ rectangular block of metal has dimensions $21\, cm$, $77\, cm$, and $24\, cm$. The block is melted into a sphere. The radius of the sphere is .......... $cm$. (Take $\pi = \frac{22}{7}$)

$A$ hollow hemispherical bowl is made of silver with its outer radius $8\, cm$ and inner radius $4\, cm$. The bowl is melted to form a solid right circular cone of radius $8\, cm$. The height of the cone formed is......$cm$

$A$ 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 $cm$)

$A$ right circular cylinder has a height of $18 \, cm$ and a radius of $7 \, cm$. The cylinder is cut into three equal parts by $2$ cuts parallel to the base. What is the percentage increase in the total surface area (in $\%$)?