Answer: 8:9
Step-by-step explanation: Two find this answer, you need to see what will be the greatest number they can divide by (greatest common divider), it needs to be the same number for both 18 and 16. What number can go into both numbers, and is the greatest number? The answer is two, now you divide 2 by 18 and 16, so you'll get 8:9.
Hope this helps have a BLESSED and wonderful day! :-)
-Cutiepatutie
