The length and breadth of a rectangle are increased by $10 \%$ and $20 \%$ respectively. What will be the percentage increase in the area of the rectangle (in $\%$)?

In a parallelogram,the lengths of adjacent sides are $12\, cm$ and $14\, cm$,respectively. If the length of one diagonal is $16\, cm$,then find the length of the other diagonal (in $cm$).

The diameter of a circle is $105 \, cm$ less than its circumference. What is the diameter of the circle? (in $cm$)

In a circle of radius $42\, cm,$ an arc subtends an angle of $72^{\circ}$ at the centre. The length of the arc is.....$cm$ (in $.8$)?

The circumference of a circular field is $440 \, m$. $A$ circular path of $10 \, m$ width runs around the outside of the field. Find the cost of gravelling the path at the rate of $70 \, \text{paise}$ per square metre? (in $Rs.$)

$A$ 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