Cast iron is an alloy composed primarily of iron together with smaller amounts of other elements including carbon, silicon, sulfur, and phosphorus. The carbon occurs as graphite, which is soft, or iron carbide, which is very hard and brittle. The type of cast iron produced is determined by the amount and distribution of carbon in the iron. Five types of cast iron are identifiable. These are gray, compacted graphite, ductile, malleable, and white. In malleable cast iron the carbon is present as discrete graphite particles. Assume that in a particular casting these particles average 20 per square inch. Would it be unusual to see a area of this casting with fewer than two graphite particles? Explain, based on the probability involved. (Based on "Space Age Metal: Cast Iron," J. Lalich, Mines Magazine, February, 1982, pp. 2-6.)