If the length of one diagonal of a rhombus is $80 \%$ of the length of the other diagonal,the area of the rhombus is how many times the square of the length of the longer diagonal?

In the given figure,$PQR$ is a triangle and quadrilateral $ABCD$ is inscribed in it. Given $QD = 2 \text{ cm}$,$QC = 5 \text{ cm}$,$CR = 3 \text{ cm}$,$BR = 4 \text{ cm}$,and $PB = 6 \text{ cm}$. What is the area (in $\text{cm}^2$) of the quadrilateral $ABCD$?

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

Mid-points of a triangle containing sides $12 \, cm$,$18 \, cm$,and $26 \, cm$ are joined to each other. Find the area of the triangle formed by joining the mid-points.

The perimeter of an isosceles triangle is $306\, m$ and each of the equal sides is $\frac{5}{8}$ of the base. Find the area.

The area of the floor of a rectangular hall of length $40\, m$ is $960\, m^{2}$. Carpets of size $6\, m \times 4\, m$ are available. How many carpets are required to cover the hall?