On increasing the diameter of a circle by $40\%$, its area will be increased by

In figure, a circle is inscribed in a square of side $5 \mathrm{cm}$ and another circle is circumscribing the square. The ratio of the area of outer circle to the inner circle is:

In figure, the area of shaded region (in $\mathrm{sq}. \mathrm{units}$) is:

In figure, the area $APD$ and $BQC$ are semicircles of radius $7 \mathrm{cm}$. The area of shaded region (in ${\mathrm{cm}}^2$) is

The area of the ring given alongside in figure is: