In measuring the sides of a rectangle,one side is taken $5 \%$ in excess,and the other $4 \%$ in deficit. Find the error percent in the area calculated from these measurements. (in $\%$)

$\Delta ABC$ is similar to $\Delta PQR$. The length of $AB$ is $16 \ cm$ and the length of the corresponding side $PQ$ is $9 \ cm$. If the area of $\Delta ABC$ is $1024 \ cm^2$,what is the area of $\Delta PQR$ in $cm^2$?

The radius of a right circular cylinder is increased by $50 \% .$ Find the percentage increase in volume (in $\%$)?

The area of the circumcircle of an equilateral triangle is $3 \pi \, cm^2$. The perimeter of the triangle is

The length of a rectangular plot is $20 \ m$ more than its breadth. If the cost of fencing the plot at $₹ 26.50/m$ is $₹ 5300$,what is the length of the plot in metres?

The wheel of a scooter has a diameter of $70\, cm$. How many revolutions per minute must the wheel make so that the speed of the scooter is kept at $66\, km/h$?