Answer:
34 cats, 21 dogs
Explanation:
cats: dogs
2 : 3
Multiply by 12 to get 24 cats
2*12 = 24 3*12 = 36 so the first is correct
Multiply by 18 to get 36 cats
2*18 = 36 cats 3*18 = 54 dogs so the second is correct
Multiply by 15 to get 30 cats
2*15 = 30 3*15 = 45 so the third is correct
Multiply by 17 to get 34 cats
2*17 = 34 3*17 = 51 so the fourth is incorrect