Each edge of a cube is increased by $50 \%$. Then,the percentage increase in its surface area is (in $\%$)?

$A$ typist uses a sheet measuring $20\, cm \times 30\, cm$ lengthwise. If a margin of $2\, cm$ is left on each side and a $3\, cm$ margin on top and bottom,the percent of the page used for typing is

The length of each side of an equilateral triangle is $12\, cm$. The height of the triangle is

$A$ wire is looped in the form of a circle of radius $28\, cm$. It is bent again into a square form. What will be the length of the diagonal of the largest square possible thus?

The two adjacent sides of a parallelogram are $60 \, m$ and $40 \, m$ and one of the diagonals is $80 \, m$ long. The area of the parallelogram is

The circumference of two circles is $132\, m$ and $176\, m$ respectively. What is the difference between the area of the larger circle and the smaller circle? (in $sq\,m$)