To find the total number of animals when the ratio of cats to dogs is 12 to 18 and there are 36 cats, you can set up a proportion:
12 cats / 18 dogs = 36 cats / x (total animals)
Now, cross-multiply:
12 * x = 36 * 18
12x = 648
Now, divide both sides by 12 to find x (the total number of animals):
x = 648 / 12
x = 54
So, there are a total of 54 animals when there are 36 cats and the ratio of cats to dogs is 12 to 18.