The concept is as follows:

It is called**ratio between quantities of the same species**the quotient between the numbers expressing the measurements of these quantities in the same unit.

Examples:

**1)** Calculate the ratio of the height of two children, knowing that the first has a height h_{1}= 1.20m and the second has a height h_{2}= 1.50m. The ratio between heights h_{1} and h_{2} is given by:

**2)** Determine the ratio between the surface areas of the volleyball and basketball courts, knowing that the volleyball court has an area of 162m^{2} and basketball has an area of 240m^{2}.

Reason between volleyball and basketball court area: .

Next: Reasons Between Quantities of Different Species