At a dog park there are 12 golden retriever and 20 poodles what is the ratio of golden retriever to poodles

You need to find a number that 12 and 20 share so you go through all the number starting with 1 and go until you can find one so I'll use the numbers 2 and 4. Gives you two options.

12/2=6

20/2=10

6:10

12/4=3

20/4=5

3:5