The diagonals of a parallelogram ABCD intersect at O. A line through O intersect AB at X and DC at Y. if AB = 12 cm, AD = 6 cm, and OX = 4 cm, find the length of OY.

The Ferris Wheel at the school fair has radius of 8 metres. It revolves at the rate of one revolution per 2 minutes. How many seconds does it take a rider to travel from the bottom of the wheel to a point 4 vertical metres above the bottom?

A cone made completely of metal (i.e. it is not hollow) has a base radius of 16 cm, and height of 8 cm. If we melt it and recast it into a sphere, what will be the radius of sphere?

A cube is painted with green colour on its five faces. If this cube is cut into equal 216 small cubes, how many small cubes will have at least one face coloured?