Final answer:
The number of blue marbles in the bag is 16.
Step-by-step explanation:
To find the number of blue marbles, we can set up a proportion using the given ratio. Since the ratio of red to blue marbles is 3:2, we can write it as 3/2. We know that there are 25 red marbles, so we can set up the proportion as:
3/2 = 25/x, where x represents the number of blue marbles.
By cross-multiplying, we get: 3x = 2 * 25 = 50
Dividing both sides by 3, we find that x = 50/3 = 16.67
Since we cannot have a fraction of a marble, we can conclude that there are 16 blue marbles in the bag.