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 $66\, km/h$?

$A$ circular road runs around a circular garden. If the difference between the circumference of the outer circle and the inner circle is $44\, m$,then find the width of the road in $m$.

If the ratio of areas of two squares is $225: 256,$ then the ratio of their perimeters is

If the length of a rectangle is increased by $10 \%$ and its breadth is decreased by $10 \%,$ then its area

$ABCD$ is a cyclic quadrilateral. $AB$ and $DC$ when produced meet at $P$. If $PA = 8 \ cm$,$PB = 6 \ cm$,and $PC = 4 \ cm$,then the length (in $cm$) of $PD$ is:

On decreasing each side of an equilateral triangle by $2\, cm$,there is a decrease of $4\sqrt{3}\, cm^2$ in its area. The length of each side of the triangle is.........$cm$.