it depends on the area that each guinea pig takes up if each guine pig takes up x area we find the total area
area=lenth times widh legnt=9 width=4 area=9 times 4=36
number of gunnie pigs that you can use equation: area of guinie pigs times number of guine pigs=total area area of 1 guine pig times x=36 divide both sides by area of 1 guinepig x=36/(area of 1 guinie pig)
therfor we find the number that can fit by dividng 36 by the area of 1 guinie pig