A bag with 12 marbles has 5 yellow marbles, 3 blue marbles, and 4 red marbles. A marble is chosen from the bag at random. What is the probability that it is yellow?
The probability of choosing a yellow marble is given by the ratio of the number of yellow marbles to the total number of marbles in the bag.
Number of yellow marbles = 5
Total number of marbles = 12
Therefore, the probability of choosing a yellow marble is 5/12.