Two circles touch externally. The sum of their areas is 41π square cm. If the distance between their centres is 9 cm, then what is difference between their diameters?

A tub is in the shape of a frustum of a cone. The radii of…

How many silver coins, 3.5 cm in diameter and of thickness 4 mm, must be…

A cubical block of side 14 cm is surmounted by a hemisphere of radius 7…

3 cubes each of volume 343 cm³ are joined end to end. What is the…

A cone of height 16 cm and diameter 14 cm is mounted on a hemisphere…