Each edge of a cube is increased by $50 \%$. Then,the percentage increase in its surface area is (in $\%$)?

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.........$cm/sec$.

The area of a rhombus is $150 \, cm^2$. The length of one of its diagonals is $10 \, cm$. The length of the other diagonal is ....... $cm$.

If the radius of a circle is reduced by $40 \%$,then its circumference is reduced by (in $\%$).

The length and breadth of a rectangular field are in the ratio $5: 3.$ If the cost of cultivating the field at $25$ $paise$ per square metre is ₹ $6000,$ then find the dimensions of the field.

If the radius of one circle is $12$ times the radius of another,how many times does the area of the greater circle contain the area of the smaller circle?