If you have sticks which measure 1, 2, 3, 4, 5, 6, 7, 8 and 9 cm (one of each). How many different triangles can you make using three of the sticks?
How many coins of 1.4 cm in diameter and 0.4 cm thick are to be melted to form a right circular cylinder of height 16 cm and diameter 3.5 cm?