Answer:
9. Correct 12. Incorrect, it's D
Explanation:
9. There is a 1:2 ratio of blue to red paint to create the shade of purple, so 6:12 would follow the 1:2 ratio so it's correct.
12. 6:14 can be simplified to 3:7 ratio. 8:16 doesn't follow 3:7 (it follows 1:2) so it can't be the right answer. 12:28 follows the ratio so it's right.