If the area of a square increases by $69 \%$,then the side of the square increases by (in $\%$)

$A$ man runs round a circular field of radius $50\, m$ at the speed of $12\, km/hr$. What is the time taken by the man to take twenty rounds of the field? (in $minutes$)

$A$ square is inscribed in a circle whose radius is $4\, cm$. The area of the portion between the circle and the square is

Four equal-sized circular plates of maximum diameter are cut off from a square paper sheet of area $784 \, cm^2$. The circumference of each plate is ...... $m$.

The radius and vertical height of a cone are $5 \text{ cm}$ and $12 \text{ cm}$ respectively. Then its lateral surface area is? (in $\text{cm}^2$)

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?