Answer:
Hello There!!
Explanation:
First look at the ratios the red marbles ratio is 4 and the blue marbles ratio is 3.
You already know that there are 12 ratios in the bag so 12÷4=3(1 ratio equals 3 marbles)
Therefore,3×3=9.So the answer is 9 blue marbles.
hope this helps,have a great day!!
~Pinky~