The walls and ceiling of a room $7 \mathrm{m}$ long, $5 \mathrm{m}$ wide and $3.5 \mathrm{m}$ high are covered with paper $6 \mathrm{d}\mathrm{m}$ wide. Find the length of paper required, if no length less than a $\mathrm{metre}$ can be bought.

$60$ square tiles of equal size were needed to cover a floor area of $135$ $\mathrm{square} \mathrm{meters}$. What is the length of each tile?

Find the area of the shaded portion in ${\mathrm{m}}^2$.

Find the area of the shaded portion in ${\mathrm{m}}^2$.

Find the area of the shaded portion in ${\mathrm{m}}^2$.

Find the area of the shaded portion in ${\mathrm{m}}^2$.

A sheet of paper measures $25 \mathrm{cm}$ by $20 \mathrm{c}\mathrm{m}$. A strip $2 \mathrm{c}\mathrm{m}$ wide is cut from it all around. Find the area of the remaining sheet and also the area of the strip cut out.

The side of a square flower bed is $1 \mathrm{m} 80 \mathrm{cm}$ long. It is enlarged by digging a strip $20 \mathrm{c}\mathrm{m}$ wide all around it. Find the area of the enlarged flower bed and also the increase in area of the flower bed.

If the area of the crossroads at right angles to each other through the centre of the field is $k m^2$. Find the value of $k$.