We have three types of Water Fowl. Canadian Geese(5), Cranes(3) and Mallards(12). If we add all of them together, we're going to get the total of water fowls.
[tex]5+3+12=20[/tex]The fraction that represents the percent of Mallards is given by the ratio between the amount of Mallards Water Fowls and the total amount of Water Fowls, which is
[tex]\frac{12}{20}[/tex]To simplify this fraction, we divide both numerator and denominator by 4.
[tex]\frac{12}{20}=\frac{12/4}{20/4}=\frac{3}{5}[/tex]The fraction that represents the water that are Mallards is 3/5.