If the curved surface area of a cone is thrice that of another cone and the slant height of the second cone is thrice that of the first,find the ratio of the area of their bases. (in $:1$)

The area of a circle is increased by $22\, cm^{2}$ when its radius is increased by $1\, cm$. The original radius of the circle is.......$cm$.

In a swimming pool measuring $90\, m$ by $40\, m$,$150$ men take a dip. If the average displacement of water by a man is $8\, m^3$,what will be the rise in water level? (in $cm$)

In $\triangle ABC,$ a line parallel to side $BC$ intersects sides $AB$ and $AC$ at points $D$ and $E$ respectively. Point $D$ divides $AB$ in the ratio $1:4.$ If the area of $\triangle ABC$ is $200 \text{ cm}^2,$ what is the area (in $\text{cm}^2$) of quadrilateral $DECB$?

Three metal cubes with edges $6\, cm$,$8\, cm$,and $10\, cm$ respectively are melted together and formed into a single cube. Find the side of the resulting cube (in $cm$).

$A$ lawn is in the shape of a rectangle of length $60 \ m$ and width $40 \ m$. Inside the lawn,there is a footpath of uniform width $1 \ m$ bordering the lawn. The area of the path is ....... $m^2$.