The number of marble slabs of size $20\, cm \times 30\, cm$ required to pave the floor of a square room of side $3\, m$ is:

Wheels of diameters $7\, cm$ and $14\, cm$ start rolling simultaneously from $X$ and $Y$,which are $1980\, cm$ apart,towards each other in opposite directions. Both of them make the same number of revolutions per second. If both of them meet after $10\, seconds$,the speed of the smaller wheel is.........$cm/sec$.

One of the diagonals of a rhombus is double the other diagonal. Its area is $25\, cm^{2}$. The sum of the diagonals is.......$cm$

The length of a rectangle is twice the diameter of a circle. The circumference of the circle is equal to the area of a square of side $22\, cm$. What is the breadth of the rectangle if its perimeter is $668\, cm$? (in $cm$)

Find the length of a rope by which a cow must be tethered in order that it may be able to graze an area of $9856 \, m^{2}$. (in $m$)

$A$ field is in the shape of a parallelogram. Its adjacent sides and one diagonal are $65 \, m$,$119 \, m$,and $156 \, m$ respectively. Find the cost of gravelling it at the rate of $₹ 10$ per $m^2$ (in $Rs.$).