It follows, for example, that the ratio of two extensive properties is an intensive property. To illustrate, consider a system having a certain mass, m , and volume, V . The density, ρ ρ is equal to mass (extensive) divided by volume (extensive): ρ ρ = m V . If the system is scaled by the factor λ λ , then the mass and volume become λ λ m and λ λ V , and the density becomes ρ ρ = λ λ m λ λ V ; the two λ λ s cancel, so this could be written mathematically as ρ ρ ( λ λ m , λ λ V ) = ρ ρ ( m , V ) , which is analogous to the equation for F above.