Seven equal cubes each of side $5 \, cm$ are joined end to end. Find the surface area of the resulting cuboid? (in $cm^2$)

If a square is inscribed in a circle,the ratio of the area of the circle and the square is

$D$ and $E$ are points on sides $AB$ and $AC$ of $\Delta ABC$. $DE$ is parallel to $BC$. If $AD:DB = 2:3$,what is the ratio of the area of $\Delta ADE$ to the area of quadrilateral $BDEC$?

The volume of a cylinder is $448 \pi \, cm^3$ and its height is $7 \, cm$. What are its lateral surface area and total surface area?

$A$ rectangular park is $65\, m$ long and $50\, m$ wide. Two cross paths,each $2\, m$ wide,are to be constructed parallel to the sides. If these paths pass through the centre of the rectangle and the cost of construction is ₹ $17.25$ per $m^2$,then find the total cost involved in the construction (in ₹).

$A$ tank is $25 \ m$ long,$12 \ m$ wide and $6 \ m$ deep. The cost of plastering its walls and bottom at $75 \ paise/m^2$ is (in $Rs.$)