The ratio of red marbles to blue marbles in a bag is 2 to 3. Which of the following statements must be true?
There are exactly 2 red marbles and 3 blue marbles in the bag.
The total number of marbles in the bag is 5.
The number of blue marbles is 1.5 times the number of red marbles.
If 1 red marble is added to the bag, the ratio of red marbles to blue marbles will become 3 to 3.
