Third part: I think the ratio is 7:12. I found the lowest common multiple, which is 13.
91 dogs divided by 13 is 7.
156 pets overall divided by 13 is 12.
Thus, the answer of 7:12.
Hope this helps! Make sure you show your work, for example the addition, multiplication, and division parts of it. :) It shouldn't be too hard, unless you want me to do that as well.