How many times will a wheel of diameter $105\, cm$ rotate in covering a distance of $330\, m$? (in $revolutions$)

The sides of a triangle are in the ratio $\frac{1}{4}: \frac{1}{6}: \frac{1}{8}$ and its perimeter is $91\, cm$. The difference of the length of the longest side and that of the shortest side is

In a triangle $ABC$,$AB + BC = 12 \text{ cm}$,$BC + CA = 14 \text{ cm}$,and $CA + AB = 18 \text{ cm}$. Find the radius of the circle (in $\text{cm}$) which has the same perimeter as the triangle.

The diameter of a circular wheel is $7\, m$. How many revolutions will it make in travelling $22\, km$?

The areas of a square and a rectangle are equal. The length of the rectangle is greater than the side of the square by $5 \text{ cm}$ and the breadth is less than the side of the square by $3 \text{ cm}$. Find the perimeter of the rectangle (in $\text{cm}$).

In trapezium $ABCD$,$AB || CD$ and $AB = 2 \, CD$. Its diagonals intersect at $O$. If the area of $\Delta AOB = 84 \, cm^2$,then the area of $\Delta COD$ is equal to (in $cm^2$)