Answer:
1. 1:3
2: 2:1
3. 1:4
4. 3:1
5. 1:2
6: 3:1
7. 1:2
Explanation:
Since my last answer was deleted by a moderator, I'm going to answer again with a more in-depth explanation for anyone who may look at this question in the future.
The easiest way to think of this is the same way as simplifying fractions. You're reducing each ratio to the lowest numbers that you can while still keeping the numbers in the same proportion to eachother.
For example, 8:12 can be thought of as 8/12. To simplify this, we would simply divide. So 8/12 could be simplified to 4/8 by being divided by 2, then 2/4, then 1/2. So 8:12 can be reduced to 1:2. Hopefully this is a better explanation.